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Discuss pump on solid fuel to overcome pipe drop in the Oil and Solid Fuel Forum area at PlumbersForums.net

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Hi
Looking at some time connecting my solid fuel boiler up to HW cylinder, problem i have is where cylinder is the first floor drops by about 350mm
so can not get a continues rise in pipe work, attached should be a diagram i think would overcome this issue, can you see any issues with what i have drawn? if the pump was to fail it is on the return side so if water in boiler got too hot the is no restriction to the vent pipe, also the is the heat sink rad, but not sure if the pump been in that position if it failed would restrict the return to much from the heat sink rad, if i put the pump before the return do you think the pump would interfere with the return as it would be positive pressure,
Thanks
John
 

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What part of the country you in? Just want to make sure nowhere near me.

This is not a DIY job, it needs a competent, experienced individual to sort it.
 
Can’t have a drop or trap
 
so what your saying is basically the solid fuel boiler can not be connected to the cylinder because of a 350mm drop and a circulation pump wouldn't over come the problem, and the is no other way round it?
 
so what your saying is basically the solid fuel boiler can not be connected to the cylinder because of a 350mm drop and a circulation pump wouldn't over come the problem, and the is no other way round it?
Not saying there isnt a way round it, just that your way isnt it.
 
Not a 'competent person', but have seen a few woodburner systems. I'm not commenting on your specific house, so take these as general comments.

I wouldn't rely on a cylinder to be the primary circulation as once the cylinder is hot, convection goes down to near zero anyway. You need 2 things: constant circulation (by gravity) AND a vent. You are correct to say the pump must not be on the heat-leak circuit. You can use separate tappings for gravity and pumped circulation at the boiler, or go down the injector tee path which would ensure you don't have the risk of the pump fighting the convection in the gravity part of the circuit.

Who's to say the cylinder will be the the main place the heat goes anyway? You could have a gravity-fed radiator which, if large enough, could be your primary circulation [edit: need to make sure this CANNOT airlock] and then you will pump everything else. If your system is designed such that the cylinder is no longer integral to the safety of the system, then there's no real reason not to have the cylinder pumped on drops.

22mm is almost certainly too small for the vent. Imagine the water in the boiler expanding to 1600x its volume and you'll understand why we like to overengineer for the worst thing that might happen. The risk with this kind of system is that gravity systems have become a niche product, and not everyone understands them now, so sometimes normal practice will not be safe.
 
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so what your saying is basically the solid fuel boiler can not be connected to the cylinder because of a 350mm drop and a circulation pump wouldn't over come the problem, and the is no other way round it?

Correct the flow always has to rise and return has to drop / fall back to burner can’t have a pump on it to push / get over a drop / trap as you always need flow else it’s a bomb

Other than boxing in so that the flow always rises and return drops etc no

Or move the cylinder/ thermal store
 
Correct the flow always has to rise and return has to drop / fall back to burner can’t have a pump on it to push / get over a drop / trap as you always need flow else it’s a bomb

Other than boxing in so that the flow always rises and return drops etc no

Or move the cylinder/ thermal store
Forgetting the pump, what would be the difference from my 350mm drop, and solid fuel boiler on ground floor with flow and return rising up to the attic running across the attic then down to a cylinder on the first floor?
 
Forgetting the pump, what would be the difference from my 350mm drop, and solid fuel boiler on ground floor with flow and return rising up to the attic running across the attic then down to a cylinder on the first floor?

You can’t run it up and back down as gravity doesn’t work like that

1667435193898.gif
 
What sort of boiler are we talking about? Because we're all assuming it's an uncontrolled heat source that relies on gravity for safety... but it may not necessarily be so!
 
You can’t run it up and back down as gravity doesn’t work like that

View attachment 78856

You can’t run it up and back down as gravity doesn’t work like that

View attachment 78856
See attached picture, it shows solid fuel boiler on ground floor, gravity flow and return pipe going up to the attic, across the attic down to the cylinder on the first floor, this still works at the cylinder is higher than the boiler, plus how could it possibly be a bomb as you have a vent pipe on the heights point of the flow pipe, or do you think the Heating and Plumbing association of Ireland have got it wrong?
 

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That’s way different that having a drop and rise / trap before the header thank hence if it boils will have no where to go hence bomb as the drop / rise won’t flow so acts like a trap, trapping the water

If you look on the flow there’s a safety discharge/ valve and the feed teed into the return at boiler so if does boil the tank will refill with cold and safety will blow the boiling water out

It’s not the best design but will work but normally find it’s noisier as the flow has to cool a bit for it to drop and start the circulation on start up

Also we’re not in Ireland hetas is our solid fuel body
 
That’s way different that having a drop and rise / trap before the header thank hence if it boils will have no where to go hence bomb as the drop / rise won’t flow so acts like a trap, trapping the water

If you look on the flow there’s a safety discharge/ valve and the feed teed into the return at boiler so if does boil the tank will refill with cold and safety will blow the boiling water out

It’s not the best design but will work but normally find it’s noisier as the flow has to cool a bit for it to drop and start the circulation on start up

Also we’re not in Ireland hetas is our solid fuel body
Yes i see what you mean about the rise back up to the cylinder, if in the rise to the cylinder instead of a elbow in to the cylinder you put a tee on then had a second vent pipe going up that would solve the problem of trap for the hot water would it not? so then on the flow the would be a vent on the drop and a vent on the rise up to the cylinder, and also put the safety discharge on as diagram, could you see any issues with that
 

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That’s way different that having a drop and rise / trap before the header thank hence if it boils will have no where to go hence bomb as the drop / rise won’t flow so acts like a trap, trapping the water

The OP's original drawing didn't have a drop and rise before the header tank?
If you look on the flow there’s a safety discharge/ valve and the feed teed into the return at boiler so if does boil the tank will refill with cold and safety will blow the boiling water out

It’s not the best design but will work but normally find it’s noisier as the flow has to cool a bit for it to drop and start the circulation on start up

Yeah, there's an injector tee on the pumped side which should start the gravity cylinder going. Agree it's not a perfect design if the cylinder is to be the primary heat dump (which I disagree with doing anyway).

Also we’re not in Ireland hetas is our solid fuel body
Long version... HETAS has not got the monopoly on competent persons for solid fuel but we all think of HETAS because they have a certain regulatory power and like to pretend only HETAS installers are deemed 'competent persons', but other schemes exist.

The OP has now done a revised drawing in which he asks if there any issues. Yes... the heat leak radiator will airlock unless he fits some kind of autobleed (the Aladdin type will work but then it takes so long to reopen once it has closed, it's not a reliable way of ensuring there is always circulation so the cylinder becomes the main circulation). 2 times 22mm could be argued to be equivalent to 28mm as a vent, but as one is across the drop, it's not necessarily going to be free to vent the boiler if it boils. Safety aside, I'm not convinced the cylinder in that latest sketch will gravity circulate and there is no pump in the system.

I'm going to be honest. It is possible to get gravity circulation where there are drops. I have seen it working. What I'm not sure is whether I have fully understood the mechanism, and I feel a need to set up a test rig to check if I've understood or not. But the one I have seen uses, I think, the gravity circulation of a cold cylinder to kick-start the gravity circulation in a small radiator. I'm not entirely sure it's 100% safe, but as the boiler is a backboiler in a rubbish and inefficient woodburning stove and the owner keeps burning wet wood, I doubt boiling is likely.
 
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Long version... HETAS has not got the monopoly on competent persons for solid fuel but we all think of HETAS because they have a certain regulatory power and like to pretend only HETAS installers are deemed 'competent persons', but other schemes exist.

True building control will also cert it but op isn’t qualified so no go either way also building control want to see it’s been installed a qualified person
 
True building control will also cert it but op isn’t qualified so no go either way also building control want to see it’s been installed a qualified person
I was thinking of OFGEM actually. They tells me they have a solid fuel competent person scheme. In the case of the OP, he could, surely DIY it and notify it to BC, but I'm not convinced he has the knowledge to design the system in a way that BC will deem acceptable.

Out of interest, Shaun, on that Irish Heating and Plumbing Association drawing, just near the vent tee, can you make out what the weird bit that connects the flow and the return together is? Looks like CCTs, but that doesn't make sense to me.
 
My guess / thought is a temperature bypass but tbh not the best design as there’s no heat leak once the cylinder is upto temp and not enough pipework losses to stop it overheating / safety valve blowing

I would want a temperature bypass or 2 n/o port valve with a stat on the cylinder to a heat leak the same size as the max stove cap
 
I would want a temperature bypass or 2 n/o port valve with a stat on the cylinder to a heat leak the same size as the max stove cap
Agreed. I've lived in a house with a woodburning stove and backboiler. It did a tremendous job of heating the Primatic-type cylinder, but it didn't actually have a heat leak radiator, so the only sensible thing to do was to let the fire go out when the cylinder was hot. The firebox and backboiler were both small so serious overheating was not possible unless you persisted in stoking the firebox once you heard the backboiler kettling, but this also meant that you could only ever really have it alight for 2 hours (4 if you had a bath at half-time)..

It relied on user understanding for safety, which isn't the British way. Italian unvented cylinders with a woodburning firebox largely rely on the same principal: tiny firebox and a dial gauge with a red zone that you try not to let the pointer needle go into, so perhaps Ireland takes the same approach that you need to be competent (in the general sense of the word) to use solid-fuel stoves, whereas in the UK we only need to be competent (in the construction sense of the word) to install them.

Back to your normally open 2-port valve, I think that is probably the best way for this kind of system. Then, if the heat leak rad has to be in an undesirable location (for example if you live in a bungalow), it only gets heated when the pumped circuit fails (in a way, the ideal would be to have the heat leak directly above the stove so when everything else is off, the effect is to heat the room the stove is in as if it were just a plain old stove).
 
Thanks Shaun / Ric for your replies, not like the first reply of (What part of the country you in? Just want to make sure nowhere near me) that sort of comment doesn't help anybody,
Probably my fault for providing a crap drawing, at the moment its just in the early stage and the drawing was mainly looking about getting over that 350mm drop so didn't mark on as much detail as i should have done,
i know probably best to put cylinder in the loft but don't want to do that till i renovate the house in a couple of year, then will probably go to unvented with thermal store and possibly solar, the house is made of 3ft thick stone walls,

the comment about get a professional in the problem with that the are very few proper professionals left these days and especially ones that know about old school unvented wood burner systems,
for the last 15 years my job is running building building sites that normally build 3 story large quality houses in villages, normally always use the same contractors, builders, carpenters, ground workers etc, the biggest problem we have are plumbers, we have had a gas safe registered guy nail clipping 15mm copper pipe direct to concrete blocks pre plastering with no protection, putting in waste pipe with no fall, fitting unvented cylinders with the D1 pipe been about 3 metres in length and the list just goes on,

The guys we have at moment aren't to bad do a very neat job but on the first plot i had to pick them up on using speed fit on the secondary return and no check valves on main water pipe entering the building dishwasher and washing machine, all these people have certificates to say they are fully qualified,
the problem is the collages you hand them some money they make sure you pass so their pass rates look good,
also most of the tutors at collage have no idea or experience, all they know is what they have read in a book,
all the old boys with experience in the past when their knees gave in would possibly go and teach the next generation, but now you have to have a teaching degree and who wants to do that,

before i was in the building trade i worked for a few years with a experienced plumber i went to collage did NVQ level 2 & 3 water regs and unvented certificate, the tutor at collage was a complete idiot, he was supposed to be qualified to teach plumbing and electrics, what he knew was very little what he didn't know he made up, he tried telling me a millivolt was a millionth of a volt, and again the list goes on, i did complain to the collage about him but got nowhere
the was a few people on that course that should never have passed but when finished their exams he would have them in the office to change the answers so they passed, same as the unvented cylinder i had never seen such a abortion of pipe work but again they passed, most of my knowledge came from the chap i worked for, we did everything from commercial to domestic, solar panels, treatment plants, lot of unvented cylinders and gas boilers, we did do a few log burners connected to cylinders problem is i probably didn't take as much notice as i should have done and he is no longer with us to ask,
completely useless asking any of the plumbers on site as the wouldn't have a clue ,
im not going to fit anything till iam 100% sure its safe just need a bit of help with the design, i know its not the best way but that's what i have to work with for now,
Thanks
 
Thanks Shaun / Ric for your replies, not like the first reply of (What part of the country you in? Just want to make sure nowhere near me) that sort of comment doesn't help anybody,
SimonG has the nickname Mr Shouty. He has his own way of communicating and in this case he certainly got his point across. I suppose my attitude is somewhat different as you need qualifications to do this that and the other on a heating system, but none at all to work on the brakes on your van.
Probably my fault for providing a crap drawing,
Well... now you mention it ;)
the comment about get a professional in the problem with that the are very few proper professionals left these days and especially ones that know about old school unvented wood burner systems,
Not entirely true, but depends where you are. Anywhere near Machynlleth, there are LOADS of people installing woodburners with backboilers partly due to the influence of the Centre for Alternative Technology over the years. You could try seeing who is installing woodburners as many of them will have some idea about solid fuel wet systems. Or try contacting the solid fuel association? In fairness, I have seen a professionally-installed system where someone ran a Fortic type cylinder off a woodburner (direct without a coil) which would have been okay in a soft water area, but then they also added a steel radiator which airlocked every time the household lit the stove, so I do agree a householder needs to check that professional installers know their trade.
for the last 15 years my job is running building building sites that normally build 3 story large quality houses in villages, normally always use the same contractors, builders, carpenters, ground workers etc, the biggest problem we have are plumbers, we have had a gas safe registered guy nail clipping 15mm copper pipe direct to concrete blocks pre plastering with no protection, putting in waste pipe with no fall, fitting unvented cylinders with the D1 pipe been about 3 metres in length and the list just goes on,
Yeah. Gas Safe installers aren't always the best plumbers. It would be better in some respects if the two trades were either totally combined or totally separated. Though, if we follow your thinking about the 'old boys' and experience, he's probably been installing gas pipes like that for 30 years and yet to have one leak. My own house has a gas pipe built into a brick wall and it's been like that since 1988, and possibly earlier. It's wrong but textbook says it's illegal, experience says it still works and gas installers who have visited the property say it's running under grandfather rights so long as it isn't leaking.

I can understand why you may have trouble finding good installers - I personally like the one-to-one contact with customers and dislike the fact that many builders underestimate the cost of plumbing and then push for sub-standard work so they can fit within their budget, need jobs done quickly and then postpone the day before you're supposed to start work, and the fact that in my experience they are the worst payers which has put me off rather - in fact I now refuse to work for anyone but the end customer (I may not be the only one?). Plenty of direct work for homeowners, so I'm not available for builders and I know many others in my situation are backlogged with work and would struggle to fit work for builders in. Very sad for builders who might be excellent customers that they are probably tarred with the same brush. Perhaps you just need to bit the bullet and employ directly (if that's an option, which I'm assuming it isn't else you'd have already done it)?

no check valves on main water pipe entering the building
Not legally required!
dishwasher and washing machine,
Not required... if the washing machine instructions state backflow protection is integrated in the machine and WRAS approved hoses are used to connect. In practice, I always fit check valves because the person installing the machine generally doesn't understand this and two valves are better than none if one is required.

all these people have certificates to say they are fully qualified,
the problem is the collages you hand them some money they make sure you pass so their pass rates look good,
And are under pressure to lift pass rates, even if they are council-owned because low pass rates suggest bad teachers or taking on the wrong students (even when they may also mean the college actually rightly fails those who shouldn't pass). The actual problem is that the NVQ system has very low hurdles and you can legitimately pass while knowing very little.
also most of the tutors at collage have no idea or experience, all they know is what they have read in a book,
all the old boys with experience in the past when their knees gave in would possibly go and teach the next generation, but now you have to have a teaching degree and who wants to do that,
You don't need a teaching degree to teach NVQ plumbing, but being able to teach and being able to do are different skill sets. Some people can do the job but couldn't teach for toffee. And actually, I know some old boys who still use lead solder on mains water because 'it's better' (which may be the case, but it's also illegal), don't understand how to flush out a new heating system properly and then blame the new boilers because the heat exchangers block up 'new boilers aren't reliable' they say... but their competition installs boilers that ARE reliable which suggests the problem is them and not the boilers. Sometimes experienced people spend their lives improving and learning, and sometimes they just keep doing the same thing they were taught as apprentices - it's not the same for all people.

before i was in the building trade i worked for a few years with a experienced plumber i went to collage did NVQ level 2 & 3 water regs and unvented certificate, the tutor at collage was a complete idiot, he was supposed to be qualified to teach plumbing and electrics, what he knew was very little what he didn't know he made up, he tried telling me a millivolt was a millionth of a volt, and again the list goes on, i did complain to the collage about him but got nowhere
the was a few people on that course that should never have passed but when finished their exams he would have them in the office to change the answers so they passed, same as the unvented cylinder i had never seen such a abortion of pipe work but again they passed, most of my knowledge came from the chap i worked for, we did everything from commercial to domestic, solar panels, treatment plants, lot of unvented cylinders and gas boilers, we did do a few log burners connected to cylinders problem is i probably didn't take as much notice as i should have done and he is no longer with us to ask,
completely useless asking any of the plumbers on site as the wouldn't have a clue ,
im not going to fit anything till iam 100% sure its safe just need a bit of help with the design, i know its not the best way but that's what i have to work with for now,
Thanks
Yeah. I see where you are coming from. This site looks moderately interesting. Would suggest if you are going to pursue this line of thought, you have a read on this Useful Guide: Boiler stoves & central heating PLUS LINK TO BEST BOILER STOVES - https://www.stovefitterswarehouse.co.uk/products/useful-guide-air-vent-boiler-stoves-centra-heating (note the article on heat sink radiators shows how you can have a heat sink without a cylinder) and consider your cylinder to be a secondary use of the heat as you cannot rely on anything that is on a drop. Then do a proper sketch and go through the install by non-competent person and notify to Building Control so it's checked by someone who, while they may have read it in a textbook, should at least have enough concern for his own backside that he won't sign it off until he (or she) is 100% satisfied it is safe. It's not a terribly expensive route to take.
 
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SimonG has the nickname Mr Shouty. He has his own way of communicating and in this case he certainly got his point across. I suppose my attitude is somewhat different as you need qualifications to do this that and the other on a heating system, but none at all to work on the brakes on your van.

Well... now you mention it ;)

Not entirely true, but depends where you are. Anywhere near Machynlleth, there are LOADS of people installing woodburners with backboilers partly due to the influence of the Centre for Alternative Technology over the years. You could try seeing who is installing woodburners as many of them will have some idea about solid fuel wet systems. Or try contacting the solid fuel association? In fairness, I have seen a professionally-installed system where someone ran a Fortic type cylinder off a woodburner (direct without a coil) which would have been okay in a soft water area, but then they also added a steel radiator which airlocked every time the household lit the stove, so I do agree a householder needs to check that professional installers know their trade.

Yeah. Gas Safe installers aren't always the best plumbers. It would be better in some respects if the two trades were either totally combined or totally separated. Though, if we follow your thinking about the 'old boys' and experience, he's probably been installing gas pipes like that for 30 years and yet to have one leak. My own house has a gas pipe built into a brick wall and it's been like that since 1988, and possibly earlier. It's wrong but textbook says it's illegal, experience says it still works and gas installers who have visited the property say it's running under grandfather rights so long as it isn't leaking.

I can understand why you may have trouble finding good installers - I personally like the one-to-one contact with customers and dislike the fact that many builders underestimate the cost of plumbing and then push for sub-standard work so they can fit within their budget, need jobs done quickly and then postpone the day before you're supposed to start work, and the fact that in my experience they are the worst payers which has put me off rather - in fact I now refuse to work for anyone but the end customer (I may not be the only one?). Plenty of direct work for homeowners, so I'm not available for builders and I know many others in my situation are backlogged with work and would struggle to fit work for builders in. Very sad for builders who might be excellent customers that they are probably tarred with the same brush. Perhaps you just need to bit the bullet and employ directly (if that's an option, which I'm assuming it isn't else you'd have already done it)?


Not legally required!

Not required... if the washing machine instructions state backflow protection is integrated in the machine and WRAS approved hoses are used to connect. In practice, I always fit check valves because the person installing the machine generally doesn't understand this and two valves are better than none if one is required.


And are under pressure to lift pass rates, even if they are council-owned because low pass rates suggest bad teachers or taking on the wrong students (even when they may also mean the college actually rightly fails those who shouldn't pass). The actual problem is that the NVQ system has very low hurdles and you can legitimately pass while knowing very little.

You don't need a teaching degree to teach NVQ plumbing, but being able to teach and being able to do are different skill sets. Some people can do the job but couldn't teach for toffee. And actually, I know some old boys who still use lead solder on mains water because 'it's better' (which may be the case, but it's also illegal), don't understand how to flush out a new heating system properly and then blame the new boilers because the heat exchangers block up 'new boilers aren't reliable' they say... but their competition installs boilers that ARE reliable which suggests the problem is them and not the boilers. Sometimes experienced people spend their lives improving and learning, and sometimes they just keep doing the same thing they were taught as apprentices - it's not the same for all people.


Yeah. I see where you are coming from. This site looks moderately interesting. Would suggest if you are going to pursue this line of thought, you have a read on this Useful Guide: Boiler stoves & central heating PLUS LINK TO BEST BOILER STOVES - https://www.stovefitterswarehouse.co.uk/products/useful-guide-air-vent-boiler-stoves-centra-heating (note the article on heat sink radiators shows how you can have a heat sink without a cylinder) and consider your cylinder to be a secondary use of the heat as you cannot rely on anything that is on a drop. Then do a proper sketch and go through the install by non-competent person and notify to Building Control so it's checked by someone who, while they may have read it in a textbook, should at least have enough concern for his own backside that he won't sign it off until he (or she) is 100% satisfied it is safe. It's not a terribly expensive route to take.

Cheers RIC.

I call it how I see it. Too many feckwits out there.
 
Thanks Ric for the web site link,
on the check valves, washing machines the buyers fit them self, dish washers are fitted severn Trent inspectors are still wanting check valves on dish washers
 

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Thanks Ric for the web site link,
on the check valves, washing machines the buyers fit them self, dish washers are fitted severn Trent inspectors are still wanting check valves on dish washers
I agree with Severn Trent. Since we don't know what brand of machine will be fitted (and assuming most people fitting the machines won't know about check valves or the Water Regulations), I prefer to err on the safer side too.

Interestingly, John Lewis fitted a washing machine in my house while I was abroad. The machine does not incorporate backflow protection, and the (German) manufacturer did provide a screw-on check valve the installers could have used when connecting to the appliance valve. John Lewis did not fit the supplied check valve, yet I fail to see how the installers could possibly have known that I had fitted one to the pipework upstream of the appliance valve, given that the pipework is entirely hidden behind a cupboard. In theory, this was a professional installation.
 

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