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Discuss Will a new Combi boiler improve shower flow?? in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Jkb

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As the title says. I have been going round in circles deciding what to buy or get fitted (with a raft of various advice).....the short story (so far).

I have an old Combi boiler needs replacing and, I am having a new bathroom installed in October but, I want to improve the all round shower flow in my house. I have 2 upstairs thermostat mixer showers, the hot flow on one is 2l per minute and the other is 6l per minute, (not great I know). Both shower flows were measured by me with the thermostat turned to hot water only on both at the same time and, a measuring jug (probably not massively accurate but the best I can do for now). My Combi boiler is downstairs almost directly underneath both showers.

So, the house cold input is 16l per minute, again measured at the kitchen sink with a jug so around half of that is currently heating up for use by both showers, if they are on at the same time. I had thought that a Worcester highflow 550 Cdi with its 25l per minute hot output and its internal 50l tank were right up my street and, an ideal replacement but..... not so. It would appear that my showers flow will not improve one jot, I’ll just have a good boiler with plenty hot water to call on but the water won’t get anywhere any quicker than it currently is. I’ve had 2 independent people keen to sell me this boiler but a third person now pops up stating all of the above and, recommending a pump in the attic to improve shower flow.... now I am none the wiser, I feel like I am back to square one.
any advice would be appreciated.

Cheers

J
 
Showers are really supposed to save households water but anyway. You need to test your water at 2 specific times ...
7.00am Sunday when it should be at peak and then at same time or a bit later weekdays when demand is at maximum and test it at the outside tap.
You also need to explore the relationship between pressure and volume. Oversized combis just to produce your desired result are not the way fwds..a system boiler with a pressurised cylinder is the way you need to go...however micky mouse heating outfits will avoid telling you about them because they are not competant or qualified to fit them. From the horses mouth...Rob Foster aka centralheatking.....and Wb are uck nowadays by the way
 
As per Rob above - best with an unvented cylinder if you want to improve overall flow to x2 showers.
 
As the title says. I have been going round in circles deciding what to buy or get fitted (with a raft of various advice)...the short story (so far).

I have an old Combi boiler needs replacing and, I am having a new bathroom installed in October but, I want to improve the all round shower flow in my house. I have 2 upstairs thermostat mixer showers, the hot flow on one is 2l per minute and the other is 6l per minute, (not great I know). Both shower flows were measured by me with the thermostat turned to hot water only on both at the same time and, a measuring jug (probably not massively accurate but the best I can do for now). My Combi boiler is downstairs almost directly underneath both showers.

So, the house cold input is 16l per minute, again measured at the kitchen sink with a jug so around half of that is currently heating up for use by both showers, if they are on at the same time. I had thought that a Worcester highflow 550 Cdi with its 25l per minute hot output and its internal 50l tank were right up my street and, an ideal replacement but... not so. It would appear that my showers flow will not improve one jot, I’ll just have a good boiler with plenty hot water to call on but the water won’t get anywhere any quicker than it currently is. I’ve had 2 independent people keen to sell me this boiler but a third person now pops up stating all of the above and, recommending a pump in the attic to improve shower flow.. now I am none the wiser, I feel like I am back to square one.
any advice would be appreciated.

Cheers

J

Agree with the chaps, but there is something else you need to consider.

I can virtually guarantee that your existing pipework's ability to deliver is severely restricted through the fitting of poor quality ball valves or gates valves. Regardless of the way you go, it is vital that you get your plumber to remove as many impediments to flow as possible. At the end of the day, your whole system can be severely compromised by the inadvertent use of a single flow restriction. No matter how much money you throw at it it will only ever be as good as the poorest restriction to flow that 's in the circuit.
 
Agree with the chaps, but there is something else you need to consider.

I can virtually guarantee that your existing pipework's ability to deliver is severely restricted through the fitting of poor quality ball valves or gates valves. Regardless of the way you go, it is vital that you get your plumber to remove as many impediments to flow as possible. At the end of the day, your whole system can be severely compromised by the inadvertent use of a single flow restriction. No matter how much money you throw at it it will only ever be as good as the poorest restriction to flow that 's in the circuit.

Ok, thankfully all the pipe work is fairly well exposed and all quite close to the boiler/showers
 
Yes, sorry you are absolutely right. Thanks for your steer, i am sure I will be asking for more info in the near future :)
we will be here as always, the best independant plumbing and heating advice in the Uk and beyond and we are free
Rob Foster aka centralheatking
 
Thank you JKB ;):)


No bother.

So, to ask the question, how much would fitting a new Combi boiler and unvented cylinder cost me? I know there are many variables with make/model/quality/pipework required etc..... but let’s just say bog standard stuff to get two showers working better..... I have approx £4.5k to spend, would that do?
 
You might have missed a fundamental point here...I would use a system boiler with unvented cylinder and a maybe immersion in the cylinder for times like summer when no heating required and just a small boost to get to 60c others might differ....but your in the right ball park anyway...Rob Foster aka centralheatking
 
Why do you need a new boiler your existing one can be used to heat the cylinder
 
Dont be spending money you don't need to.
A new boiler will not justify itself.
Use existing combi to do kitchen hw tap and uvc to do bathrooms. Easily done (so long as not in london) with 4.5k.

My boiler is 23 years old ;)
 
It gets serviced every year and the engineers say they don’t make these any more....it’s also close to our living area and can get very noisy when it’s working. It’s a halstead finest platinum
hmmmm. bye bye boiler halstead = dacia sandero or even a trabant centralheatking
 
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You will now be heating your hot water in a hot water cylinder as such you don’t need the instantaneous hot water from a combi boiler so get the system boiler
 
Hi,
Sorry but why?

Your speaking to the intellectually challenged here so I need as much info as possible and, at what cost? (best/worst case scenarios)
Its obvious, you are wanting high volumes of hot water a combi will just rob the unvented stored water and the system set up is ideal for your requirements ....combis are really for flats and little gaffs with one bathroom ...thats what they were designed for in Europe originally but they got railroaded in uk by basic heating outfits that dont know how to do anything else. Then the manus jumped on the bandwagon producing super combis that have a cat in hells chance of supplying the volume advertised because it is not available all the time from the utility whom have no legal responsibility to supply silly large volumes.....you could put in a conventional system with large volume high level intermediate cold water storage and never look back ...but its old fashioned ...I have one its ace.
centralheatking
 
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It gets serviced every year and the engineers say they don’t make these any more....it’s also close to our living area and can get very noisy when it’s working. It’s a halstead finest platinum

They dont make my boiler any more either, but I'll not be changing it just cos some clutz who wants to make a killing at my expense says so...

Decide whats important here will you. Your shower performance via our advice or some chap selling you a new boiler. Your home. Your choice. However, pushing/waiting for advice to match half of what someone else has said is sure to pi55 us off :rolleyes::)
 
They dont make my boiler any more either, but I'll not be changing it just cos some clutz who wants to make a killing at my expense says so...

Decide whats important here will you. Your shower performance via our advice or some chap selling you a new boiler. Your home. Your choice. However, pushing/waiting for advice to match half of what someone else has said is sure to pi55 us off :rolleyes::)

Sorry, it’s not my intention to pi55 anyone off and your advice is greatly appreciated but, is advice not something that’s fundamentally important to making the correct decision?
It’s shower performance that’s at the top of my priority and always has been. Quotes saying “it’s obvious” don’t actually help much either when in actual fact it’s defiantly not obvious (not to me anyway).
Then, after a dozen or so posts one comes back saying a system boiler is what I need to install, if it is then that’s what I’ll go for, pending further advice of course.
So, with a total outlay of about £11-12k coming up on a new bathroom with 2 decent shower outputs I’ll be pi55 img off a few more people till I get it right.
If I can take you back to the grass roots of advice, the more I have the more prepared I am at challenging the so called sales people who are knocking on my door and, are after nothing more than a commission based sale with what they want to sell me, as apposed to what I actually need i.e. British Gas quote of £4800 for a highflow 550CDi which would have made not a jot to my shower performance.
 
Sorry, it’s not my intention to pi55 anyone off and your advice is greatly appreciated but, is advice not something that’s fundamentally important to making the correct decision?
It’s shower performance that’s at the top of my priority and always has been. Quotes saying “it’s obvious” don’t actually help much either when in actual fact it’s defiantly not obvious (not to me anyway).
Then, after a dozen or so posts one comes back saying a system boiler is what I need to install, if it is then that’s what I’ll go for, pending further advice of course.
So, with a total outlay of about £11-12k coming up on a new bathroom with 2 decent shower outputs I’ll be pi55 img off a few more people till I get it right.
If I can take you back to the grass roots of advice, the more I have the more prepared I am at challenging the so called sales people who are knocking on my door and, are after nothing more than a commission based sale with what they want to sell me, as apposed to what I actually need i.e. British Gas quote of £4800 for a highflow 550CDi which would have made not a jot to my shower performance.
Just do what you like, we the collective wisdom have all advised you the route you should take, there is little more to tell you. Strangely on this one we all agree on where you should head. Best advice in uk freely given let us know what you put in and how it performs
we like feedback
Rob Foster aka centralheatking
 
Sorry, it’s not my intention to pi55 anyone off and your advice is greatly appreciated but, is advice not something that’s fundamentally important to making the correct decision?
It’s shower performance that’s at the top of my priority and always has been. Quotes saying “it’s obvious” don’t actually help much either when in actual fact it’s defiantly not obvious (not to me anyway).
Then, after a dozen or so posts one comes back saying a system boiler is what I need to install, if it is then that’s what I’ll go for, pending further advice of course.
So, with a total outlay of about £11-12k coming up on a new bathroom with 2 decent shower outputs I’ll be pi55 img off a few more people till I get it right.
If I can take you back to the grass roots of advice, the more I have the more prepared I am at challenging the so called sales people who are knocking on my door and, are after nothing more than a commission based sale with what they want to sell me, as apposed to what I actually need i.e. British Gas quote of £4800 for a highflow 550CDi which would have made not a jot to my shower performance.

Best advice you'll get on here is:
1 - Put away any preconceived ideas
2 - Do not go with BG. Their business is sales, NOT your satisfaction.
3 - Find a local plumber, set out your 'problem' (note NO opinions) and ask for their honest advice. Listen to it, heed it.
4 - If #3 does not recommend an UVC then find another.
 
Best advice you'll get on here is:
1 - Put away any preconceived ideas
2 - Do not go with BG. Their business is sales, NOT your satisfaction.
3 - Find a local plumber, set out your 'problem' (note NO opinions) and ask for their honest advice. Listen to it, heed it.
4 - If #3 does not recommend an UVC then find another.

Ok thank you. Will go for that advice. Thanks to all who chipped in. Sorry if it came across that I was not appreciative of everyone’s input, that was not my intention.
 
Ok so,
After some sound advice on here, it Looks like a 300l unvented cylinder and, Worcester 27i system boiler, some pipes both gas and water upgraded/bigger diameter, Digital controls, thermostat and some other plumber speak stuff including electrics etc.... all for £4.2k..... does that seem about reasonable?

Thanks for everyone’s input
 
Sorry, it’s not my intention to pi55 anyone off and your advice is greatly appreciated but, is advice not something that’s fundamentally important to making the correct decision?
It’s shower performance that’s at the top of my priority and always has been. Quotes saying “it’s obvious” don’t actually help much either when in actual fact it’s defiantly not obvious (not to me anyway).
Then, after a dozen or so posts one comes back saying a system boiler is what I need to install, if it is then that’s what I’ll go for, pending further advice of course.
So, with a total outlay of about £11-12k coming up on a new bathroom with 2 decent shower outputs I’ll be pi55 img off a few more people till I get it right.
If I can take you back to the grass roots of advice, the more I have the more prepared I am at challenging the so called sales people who are knocking on my door and, are after nothing more than a commission based sale with what they want to sell me, as apposed to what I actually need i.e. British Gas quote of £4800 for a highflow 550CDi which would have made not a jot to my shower performance.
If your mains pressure is high enough (i.e. your cold shower is strong enough), and you have space, I would go with an unvented plain steel cylinder that contains a single corrugated stainless or copper hot water coil. They are often called hygienic cylinders because the hot water that comes out does not sit in the tank, only in the coil, so there is no worry of legionella. This should cost around 1.5K for the cylinder, pump for the radiators, expansion vessels and bits, plus labor of course.

If you go that route, whether you change your boiler or not is an independent decision, but if you do, you don't need a combi (as Riley said), you just need a normal (system?) boiler that does not do hot water and is simpler/cheaper.

Disclaimer: I am not a plumber, but I do have decent showers. Cheers.
 

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