Householder here, pls help, downstairs rads cold, enginineer stumped after power flus

[Kaz1111]

Downstairs rads suddenly cold from about a week ago.

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

could be your pump

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Worcester GReenstar HE boiler with hot water cylinder in airing cupboard with grundfos 15/60 pump.

So, problem is that downstairs rads suddenly stone cold from about a week ago. have bled rads, no change, turned them all of upstairs to try and divert downstairs, some became warm, but certainly not hot, some still stone cold.

History - boiler changed to Worcester GReenstar He around 7 yrs ago she we moved in and some rads added/ renewed. Two rads at back of house still never heated that well so around 15 months ago decided to try and fix that. heating engineer said problem was that Grundfos pump too small, changed from 15/50 to 15/60. Since then all rads wonderfully warm till around a week ago, as above.

New heating engineer came yesterday, didn't think pump as only 15 months old. Power flushed today, said got some heat to each and every rad in the flushing process. However once system refilled and balanced, no change, downstairs rads still cold.

On telephoning Worcester for some help he says they told him should not have 'extra' grundfos pump in airing cupboard as this will 'compete' with pump in boiler and they will be fighting against each other, causing both to fail quicker than they should (is this correct?).

Therefore engineer now suggesting renewing boiler pump and taking grundfos pump out, although he did say he tried running grundfos pump only today, still no heat to downstairs rads, and then boiler pump only, and, again, still no heat to downstairs rads so surely this unlikely to solve problem?

I am wondering if We may just need a new grundfos pump and a bit cautious about just doing away with this pump as the new grundfos 15/60 15 or so months ago gave us fully hot radiators all over the house!

I would be grateful for all and any ideas as concerned that I am going to be spending a lot of money trying to fix this without a correct diagnosis as to what is actually causing the problem...

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Thanks Tom, would be great if you could spare the time to read rest of post, first one just wanted to post as have typed out about 3 times and kept saying I wasn't logged in ....

 

[jfb]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

The worcester engineer is right you can not have two pumps on the same system they will compete against each other. Sometimes a pump appears to be working but the impellors are damaged or worn. There may be a closed off or partially closed valve in the system. Sometimes gate valves can be a problem the stem snaps. Your system may need balancing water will always take the easiest route. As a rule of thumb half close the upstairs lockshields and fully open the downstairs ones. If it starts to work balance the system using a thermometer.

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

are upstairs rads as hot as normal ? you dont have a room stat on both floors is your hot water hot feel the pipes but be cateful they could be very hot do you have a bypass on the system

 

[plumber0808]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

It does sound like the pump on the boiler. also maybe blockage in system.

A bit worrying that the engineer needs worcester to tell him that there shouldn't be a extra pump fitted. That needs to be cut out but why was it fitted in the first place.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Thank you to everyone that has replied. Take the point that the engineer should know you can't run two pumps .... But he was not the one that fitted new grundfos 15 months ago at a cost of £ 360 ... However, it worked and all rads hot for first time!

Sorry if this is a daft question, I am a woman with very limited knowledge ... Do all boilers have a pump in them? Surely not, otherwise why would you have a pump in airing cupboard which so many people seem to have?

one more thing, if it helps with the detective work. Now that we have heating on '5' on boiler, it normally reads about 75 then, but keeps fluctuating now, going down to say 35 and then coming back up ( may have always done/. Should do this, but trying to spot everything now)! Would this have anything to do with pump on boiler?

So, most of you would agree pump in airing cupboard needs to go and we should be relying on pump that is in the boiler to pump the heat round whole house ?

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Also, if possible blockage, how do we remove - isn't this what the power flush is for?

Thanks for all your advice.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

And can someone give a quick explanation of what bypass is?

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

on hot water only does the temp stay high on the boiler once it has reached temperature

 

[AWheating]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

a system boiler has a pump inside it. a heat only boiler does not and you normally find the pump in the Air cupboard.

a bypass is a spring valve which is set to open at a adjustable pressure to make sure the boiler always has a min flow rate through it. Some boilers have them built in, some need an external one on the system, some will need/require both.

a powerflush is to clean the heating system, it wont always remove partial blockages especially bad ones.

 

[gassafe]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Maybe the 15 month old pump is blocked or sludged up, did the chap check when power flushing?

Where did he powerflush from? Maybe the debris was pushed into the boilers pump!

 

[plumber0808]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Thank you to everyone that has replied. Take the point that the engineer should know you can't run two pumps .... But he was not the one that fitted new grundfos 15 months ago at a cost of £ 360 ... However, it worked and all rads hot for first time!

Theres your problem ^^^ all rads hot for the first time. When were they not hot.
there is a circulation issue, pump, sludge, blockage maybe.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Thank you everyone. Tom, I will have to check when hot water only on and will let you know.

Gas Safe - power flush was done from hall radiator.

A Wheating - thanks for explanation. By heat only system you mean heats rads only and not hot water?

Plumber 0808 - so from what you say perhaps pump on boiler was not so good when grundfos one was fitted so grundfos 'extra' pump fixed the problem for a while until the use of both, one on boiler and grundfos caused one or both to fail.

So to recap - would next step be remove grundfos and replace boiler pump?

How do you locate the sludge/blockage and remove ...

Obviously my concern is that I have spent money on power flush and now need to spend some more and worried that we are going to go through a few things that are not solving problem.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Also, engineer said grundfos pump was working otherwise radiators would not heat up upstairs ... But he did also say he took silver screw off and it was working ?

 

[vern]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Lol this sounds like Zebs head wrecker thread? Same job?

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

I'm pleased its giving you a laugh guys, and its certainly wrecking my head .... But please take pity and give me some proper suggestions as to where to go next ... Or if any of you are near to South London ...

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

not always the case spindle in the pump can spin even though pump aint working or csn spin slower

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

put your hot water on how is the temp on the boiler does it rise regular or rapid

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

peeps aint laughing its text talk

 

[plumber0808]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

The 2 rads that struggled before are either, undersized pipework or sludge is restricting the flow to them. by fitting the second pump your curing a problem with another problem. Remove the second pump have a new pump fitted to the boiler.

Sometimes a power flush is not the answer as some systems are too far gone.

 

[R1CKY]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

First step should be to remove the external pump, unless you have an extremely large system I can't think why you'd need an extra pump. Just because it is rotating does not mean it is working, the fins could have snapped on the impeller. The external pump could actually be causing a restriction in the system.

The radiator he powerflushed from, what size is the pipework supplying it? Drinking straw sized or larger? If it is drinking straw sized (8 or 10mm) the powerflush will have been next to useless.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Plumber 0808, thank you. I understand what you are saying, but we were warm once the new grundfos was fitted! Will try with new pump to boiler then. By 'too far gone', does that mean replacing system, or is there something other than power flush to remove sludge.

Tom - hot water only been on for about an hour. Boiler temp seems to be fluctuating between 75 down to around 63 ...

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

you needsomeone to check the resistance on the sensors to start with k

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Thanks for all your advice guys; Ricky, no idea what size the pipe work is Im afraid....

 

[armyash]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

We had a similar problem this week, from what most here are saying the pump is playing a vital part in the problem.

That wasn't the case for us, the rads that were not working needed new valves. They were 35 years old though and had never been touched since new. Changed valves, refilled and every radiator was piping hot.

 

[jrmurray]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

It may also be worth fitting a magna clean to the system as it stops all the sludge from passing through your boiler and the rest of the system.

 

[Whyme]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

I know its late in the thread to reply but a 15/60 pump is a meaty pump which should move it round BUT like all others say there shouldnt be any reason to fit an external pump, if the boiler has one ( unless its a massive house and youve got low loss headers etc). The best course of action is like above replace internal boiler pump and get a good word of mouth firm or plumber to spend a day properly treating, flushing and cleansing ur system...good luck.

 

[Bronze_tap]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Thank you to everyone that has replied. Take the point that the engineer should know you can't run two pumps .... But he was not the one that fitted new grundfos 15 months ago at a cost of £ 360 ... However, it worked and all rads hot for first time!

Sorry if this is a daft question, I am a woman with very limited knowledge ... Do all boilers have a pump in them? Surely not, otherwise why would you have a pump in airing cupboard which so many people seem to have?

Usually older heat only ones don't have the pump, newer ones does have (especially combis). Extra pump probably was fitted to increase the preassure and push water through the blockage.

It looks like there is a VERY SERIOUS restriction(s) of the flow in the system. The chemicals used before the powerflush had loosened a few clumps of sludge, which had probably blocked the orifice... It may be in/near the pump, gate valves, boiler, its heat exchanger, sludged up droppers, anywhere (but I would suspect the main circuit first, since the boiler is cycling). You need to get yourself a Good Professional (Like user Bunker or most others on this forum)) or Good Hobby plumber (DIYer who had worked with radiators AND plumbing before, and his family/friends were pleased with his work), who is ready to spend at least 1-2 FULL DAYS overhauling the WHOLE system. He will need a hand with radiators (very likely), so have one more strong lad available.- Check the flow resistance trough each system part, flush EACH dropper/radiator INDIVIDUALLY/DIRECTLY, remove the radiator/gate valves, if there is lack of good flow. Also you'll want someone, who is ready to replace parts of piping, if they are still restricted...

Read/print this: (http://www.ukplumbersforums.co.uk/c...olution-how-do-proper-cheap-job-yourself.html), to give you some idea of the proper (after)flush, and don't leave the job unattended. If done by pro - the protocol can be varied, but still should be done THROUGHLY. The flusher connection to ONLY RADIATOR won't cut it...

If they have a power flush machine - attach it instead of the Pump, to the boiler, coil (if you've got one) and EACH dropper pair and also each radiator directly, and flush untill clear...
Do fit good magnetic filter to the boiler return at the end (may go instead of the secondary pump, if the boiler has one.

Before taking everything to bits, you can try listening for the water noise, when the pump or flusher is running - it may pinpoint the location of the blockage - noise is similar to half open tap or toilet cistern fill up (esp near the end). If it's sludge blockage, it may not be audible (longer orifice).

 

[Whyme]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

:iagree: skills.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Once again, thank you to everyone who has replied. Your advice has been invaluable.

So seems our best course of action is to remove grundfos pump and replace boiler pump. Then put on a magna clens? BUT first remove sludge/blockage ... Otherwise problem will remain?

i have read Bronze Tap's explanation of power flush, thank you. Not something I think I could attempt but is the best way to find blockage then to remove all the rads and flush through with water, wont blockage be more likely in pipes? and also read that perhaps power flush should not just have been done from hall radiator.

Should machine be attached to each rad to try to clear blockage/sludge? is there a certain protocol to be followed by heating engineers or is each 'problem' blockage treated differently? I have also taken on board the comment that power flushes are to clean system and not actually remove blockages...

Finally ... I am so sorry that this has turned into War and Peace ... And is there anyone in North Kent/SE London that could come and sort this out for me or recommend someone

 

[Dotty]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

There are a few boys out your way Kaz, hopefully they'll see this and pm you.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

well, sorry guys, I am back again!

new pump fitted to boiler today, pump in upstairs airing cupboard has been decommissioned (still in place, electrical supply cut off). Has not cured the oroblem, no change at all. We will now be going into our third week of no heating and £550 lighter! engineer said he has put some 'chemical' into system (I was on phone at time, have a relative seriously I'll in hospital, and he spoke to my partner). He has said run the system for a couple of weeks with the chemical in it ... Said after that he will have to get under floorboards and check pipe work. We have oak flooring over floorboards so he will have to get in from living room where there is carpet only over original floorboards.

Incidentally we have now noticed that when hot water only is on, the radiator in the bedroom next to airing cupboard s piping hot plus the one in the next bedroom ... He said this is strange, but they are unlikely to be fed from hot water system (then why are they boiling hot?)

Also when hot water is on temp on boiler stays constant. When heating is on temp fluctuates all the time.

Heating wen on at 1.20 pm today, changing over from hot water being on. emp on boiler went down immed fro 76 to 46 .... At 1.43 pm it read 44' 1.47 pm - 74, 1.51 - 48, 1.52 - 70, 1.53 - 76. Is this normal, should it be fluctuating like this all the time?

I am just about At the end of my tether, two kids and the coldest March since 1963 ...

I did suggest taking rads off and flushing through .. He said if a blockage more likely to be in pipe work than rads ...

 

[PhoenixServices]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Kaz they need to take out the second pump completly as just disconnecting it will leave a smaller waterways going through which wont help your problem. I had one like this the other day which turned out to be the ball on 2-port valve had expanded so valve was opening electrically but not actually opening the waterways. Either that or its a blocked return on the heating would be my guess.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Thanks Phoenix Services. I did if pump should be taken out which he said he would do initially and put a piece of pipe in to replace it but then said disconnecting it would be ok ... Is the return one of the pipes that takes the water back to boiler ? If so could be anywhere in the pipework . Sorry I know it must be a very basic question, but Im a ladyyyyyy, lol. Although I must say think I might go in for a plumbing course after all this ... :yes:

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

pump definately needs removing before you do anything else

 

[mfgs]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Where abouts are you in SE London? I may be able to take a look at it for you.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Where abouts are you in SE London? I may be able to take a look at it for you.

How did I miss that one! Didn't get an email saying had a reply ... Am in Beckenham, any good?

 

[Rickster123]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

How did I miss that one! Didn't get an email saying had a reply ... Am in Beckenham, any good?

Ahh beckenham my old home town! Not near Langley school are you? Memory lane!

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Very near. My boys attend Langley, 5 min walk in the morn ...,!

 

[Rickster123]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Ah great days! Actually they weren't! I hated school but I made my first fortune selling cigarettes and wham bars at the gates!

 

[Rickster123]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Sorry gone off topic! Hope you get it sorted.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Ha ha, no problem. Still a very good school, we moved here from another borough for school. Nice area too, station, pub, shops, nearby, but nice and quiet, what more could you ask for. Actually a nice house in Knockholt with a couple of acres but I can dream !

 

[Bronze_tap]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

well, sorry guys, I am back again!

new pump fitted to boiler today, pump in upstairs airing cupboard has been decommissioned He has said run the system for a couple of weeks with the chemical in it ... Said after that he will have to get under floorboards and check pipe work. We have oak flooring over floorboards so he will have to get in from living room where there is carpet only over original floorboards.

Incidentally we have now noticed that when hot water only is on, the radiator in the bedroom next to airing cupboard s piping hot plus the one in the next bedroom ... He said this is strange, but they are unlikely to be fed from hot water system (then why are they boiling hot?)

Also when hot water is on temp on boiler stays constant. When heating is on temp fluctuates all the time.

I assume that you've got a HW tank.
So you say that on the HW mode boiler is working fine (except the 2rads hot), but on CH cycles (flow restriction)?
Than I would suggest checking both motorized valves, inspect that the rubber ball inside each them is intact and moving freely. If some bits missing -> it is blocking somewhere in the CH pipework. (in addition to the old pumps).
Tell them to do a proper flow resistance testing with garden hose or power flusher, check for pressure differential on the pipework/boiler. Also check boiler's waterways. (but less likely, because th HW is fine). Try flushing the system in the oposite flow direction from the boiler/pump connections. (Disconnect the boiler AND the extra pump to do that.) Be ready for the black bit of rubber ~(20-18mm) to emerge

-> do get your guy to have a look at motorized valves? Also check them on the inside? (Not just replace them), make sure bals/washers haven't gone missing and blocking?

PPS: Check for possible direct bypass between the flow/return pipes (from the single pipe system days). Do this if there is NO flow resistance between the flow/return, even if all rads are off/closed.

And wish all of you good luck and Happy and Warm Easter.

 

[Kaz1111]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Today have turned all rads off apart from the two that were not heating at both ends; that is trv's to '0' and the other side with the ' pegler ferrier' top with an 'on' is now turned off. The two rads that were not working are now piping hot...

Do I now turn all the other rads back on individually one by one and see what happens? starting with the one nearest the two that are now hot, or does it not matter in which order they go back on.

Does this throw any further light on problem or are we still looking at possible circulation/sludge problem? Thank you.

 

[tom609]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

open the next radiator that is the furthest away count how many turns then turn it back a 1/4turn if all still working go to next furthest away and open fully then turn back 1/2turn and so on till they are all on good luck

 

[Bronze_tap]

Re: Householder here, pls help, downstairs rads cold, enginineer stumped after power

Today have turned all rads off apart from the two that were not heating at both ends; that is trv's to '0' and the other side with the ' pegler ferrier' top with an 'on' is now turned off. The two rads that were not working are now piping hot...

Do I now turn all the other rads back on individually one by one and see what happens? starting with the one nearest the two that are now hot, or does it not matter in which order they go back on.

Does this throw any further light on problem or are we still looking at possible circulation/sludge problem? Thank you.

circulation/sludge/blockage problem - YES it is.

So once you've blocked the easy (-er) path, the water now is working it's way to the remote rads (so we've got partial blockage). Now try turning them on one by one, and see when two coldest ones become cold/cool again. Also listen for the water noise, as you open up the valves -it will tell you that that rad probably is before the blockage (if in the pipework).

Good Luck.