Can you get a system any more wrong, and I still hate combis

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Recently bought a house - to be honest, I had a fair idea what I was getting as I already have a flat next door in the same development. Since it was built, British Gas have been in and done a nice untidy boiler replacement :rolleyes:

Anyway, my expectations were to find all the lockshields fully open, and I wasn't disappointed when I had a go at balancing the system tonight.

So, what does the advice say about balancing ? Well one step is turning down the pump to set the flow in the "slowest" rad in the system. But this is a crappy combi - so you can't do that without affecting the DHW as well.

So off round the system I go, shutting down the lockshields to try and get some semblance of system balance. I'm still in single figures when the valves are getting noisy. I give up aiming for 12˚C temperature difference and go for 10˚, then 8˚, then 6˚, and finally settle at just 5˚ at which point the bathroom and back bedroom are about at a tolerable noise level (bathroom is only 4˚).

But here's the special features of this system. It's 22mm from the boiler up into the upstairs floor, and it arrives at the rads as 10mm. Clearly the small front room upstairs is fed from two pipes which are touching and not lagged - the flow temp is a full 15˚ less than some other rads ! The living room downstairs has pipes dropped from upstairs - buried direct in the plaster down the wall. Lockshield fully open and it's still giving 9˚ drop, while the back bedroom is barely acceptable for noise at only 5˚. And the surface of the plaster is above 50˚ where the pipes are buried.
Just for good measure, there are two small rads in the dining area fed by their own 10mm branch tapped off close to the boiler. In this case, a full 20+˚ lower flow temperature than the other rads (and only 3˚ drop) - yup unlagged pipes run touching each other :eek:

Needless to say, except when the wether is mild and the boiler flow temp can be turned down, it's not going to be condensing very much.

I guess I'll just have to save up and get a thermal store fitted like I've done in the flat - fully TRV'd system (fully modulating pump), and above all no combi :) Needless to say, the house if built to maximise difficulty of altering anything like this :evil:
 
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He hasn't got one..........yet.

But he'll soon fix that by the sound of it. :LOL:
 
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Recently bought a house - to be honest, I had a fair idea what I was getting as I already have a flat next door in the same development. Since it was built, British Gas have been in and done a nice untidy boiler replacement :rolleyes:

Anyway, my expectations were to find all the lockshields fully open, and I wasn't disappointed when I had a go at balancing the system tonight.

So, what does the advice say about balancing ? Well one step is turning down the pump to set the flow in the "slowest" rad in the system. But this is a crappy combi - so you can't do that without affecting the DHW as well.

So off round the system I go, shutting down the lockshields to try and get some semblance of system balance. I'm still in single figures when the valves are getting noisy. I give up aiming for 12˚C temperature difference and go for 10˚, then 8˚, then 6˚, and finally settle at just 5˚ at which point the bathroom and back bedroom are about at a tolerable noise level (bathroom is only 4˚).

But here's the special features of this system. It's 22mm from the boiler up into the upstairs floor, and it arrives at the rads as 10mm. Clearly the small front room upstairs is fed from two pipes which are touching and not lagged - the flow temp is a full 15˚ less than some other rads ! The living room downstairs has pipes dropped from upstairs - buried direct in the plaster down the wall. Lockshield fully open and it's still giving 9˚ drop, while the back bedroom is barely acceptable for noise at only 5˚. And the surface of the plaster is above 50˚ where the pipes are buried.
Just for good measure, there are two small rads in the dining area fed by their own 10mm branch tapped off close to the boiler. In this case, a full 20+˚ lower flow temperature than the other rads (and only 3˚ drop) - yup unlagged pipes run touching each other :eek:

Needless to say, except when the wether is mild and the boiler flow temp can be turned down, it's not going to be condensing very much.

I guess I'll just have to save up and get a thermal store fitted like I've done in the flat - fully TRV'd system (fully modulating pump), and above all no combi :) Needless to say, the house if built to maximise difficulty of altering anything like this :evil:

Is that a clear cut question for the DIYnot regulars willing to give advice or the ramblings of a Homebuyer/DIYer ?
 
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Is that a clear cut question for the DIYnot regulars willing to give advice or the ramblings of a Homebuyer/DIYer ?
Both !

An observation that all the advice I've read on balancing radiators assumes that you can change the pump speed - which you can't on a combi without affecting the DHW. Not that I needed any more reasons to dislike them.
So, if you have a situation where the pump is too powerful and throttling down the flow results in unacceptable noise - what do you do about it ? Just leave the flow rate too high and turn the condensing boiler into a non-condensing boiler ?

Plus ramblings on the deficiencies of the installation - reinforcing negative stereotypes of plumbers as having been at the back of the queue when "nouse" was being handed out.

Of course, the question in the subject may have escaped notice ;)
 
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Roughly translated, this says that the OP is a kn*bhead.
 
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Roughly translated, this says that the OP is a kn*bhead.
Hmm, so trying to set up a system as best you can (particularly trying to get the boiler working as efficiently as it's designed to), and be impeded by crap design of the system, enhanced by crap design of combi boilers, is being a kn*bhead then ? If that's what you want to think then that says more about you than me.

So what's your answer to the problem ?
 
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install a auto bypass :idea:
Which does what to the return temp ?

In case you miss the significance of that, what is the max return temp for a condensing boiler to condense ? What would the design flow temperature have been on a system designed somewhat before condensing boilers were more than some expensive gimmick (if even on the market - dunno when they because available) ? What happens to the heating if you turn the flow temp down significantly below the design temp ?

With the non-condensing boiler originally fitted, having a bypass would not have been an issue. Fitting on to a condensing boiler simply raises the return flow temperature above the limit for condensing operation. I had thought about it ...
 
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If you had a problem with BG install, why have you not called them back, instead of trying to balance the system, obviously not knowing what you are doing, from what you have written.! :eek:

I'm not having a go, but your making a lot of assumptions, before corrections are made-professionally.
 
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install a decent quality combi (atag or viessmann for example) with a modulating pump instead of complaining that a cheap combi wont do what you want it to, every boiler is a compromise of some kind.
 
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ring bg and tell them your not happy guess what they will come out as their like that expensive but they realy do care about custmer care
i had conversation with service manger about old potterton bbu burner gone i had to class it as imdeatly dangrous due to uncontrol burn his complaint was no one told him it was it was reduced parts list
 
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