I think my new boiler is too small....

[LiamIreland]

Hi. I have just bought and renovated a house. It has 19 radiators, 3 showers and 1 bath. I can never get good heat out of all the radiators at once. I suspect the boiler that the plumber installed in not up to the job. Its an Ideal Logic Combo C30. Can anyone conform this before I raise the issue with the plumber? Also do I have any recourse re. the installer having to change it to a more suitable one for me? Thanks in advance. Liam

 

[John.g]

Maybe check that the boiler is producing 30kw as a first step, open up all the rads and when the boiler has been firing for 10 minutes or so take two gas meter readings over say a 2 minute period, if outputting 30 kw you should see a difference of ~ 0.10 M3 between readings.

 

[snowhead]

Who did the design of the system?
Were any sizes of boiler or radiators stated in the quote?
Was there an agreed room / house temperature linked with a minimum outdoor temperature?

What controls does the system have, zones with thermostats for each and or thermostatic radiator valves or smart controls of some sort?

Did you get more than one quote and did each quote state boiler sizers or any other specification?
What made you choose the plumber that did the install?

 

[ShaunCorbs]

Combi boiler for 4 bathrooms no chance

 

[LiamIreland]

Maybe check that the boiler is producing 30kw as a first step, open up all the rads and when the boiler has been firing for 10 minutes or so take two gas meter readings over say a 2 minute period, if outputting 30 kw you should see a difference of ~ 0.10 M3 between readings.

Thank you, I'll try that tomorrow and see what it says.

 

[LiamIreland]

Who did the design of the system?
Were any sizes of boiler or radiators stated in the quote?
Was there an agreed room / house temperature linked with a minimum outdoor temperature?

What controls does the system have, zones with thermostats for each and or thermostatic radiator valves or smart controls of some sort?

Did you get more than one quote and did each quote state boiler sizers or any other specification?
What made you choose the plumber that did the install?

He was the only plumber I could get and he just said that he would sort out the system for me. I should have done more due diligence, but that ship has sailed now and I just want to figure out if the boiler is up to the job.

 

[exedon2]

Maybe check that the boiler is producing 30kw as a first step, open up all the rads and when the boiler has been firing for 10 minutes or so take two gas meter readings over say a 2 minute period, if outputting 30 kw you should see a difference of ~ 0.10 M3 between readings.

All logic combi's have a max output to heating of 24kw.

 

[JC22024]

What age is the property? How well insulated are the Floors, Walls & Ceilings?

 

[LiamIreland]

What age is the property? How well insulated are the Floors, Walls & Ceilings?

Property is 1990, has cavity wall insulation and some insulation in the eaves and ceiling. Not up to modern guidelines I would imagine. Top rads can get very hot (as I would like) downstairs warmish at top but over all much cooler. Thanks for replying.

 

[oz-plumber]

I agree with you.....too small.

Not a great choice of installing a combi boiler for the domestic hot water side either.

Were you advised this was the way to go or did you ask for a combi.

 

[John.g]

Property is 1990, has cavity wall insulation and some insulation in the eaves and ceiling. Not up to modern guidelines I would imagine. Top rads can get very hot (as I would like) downstairs warmish at top but over all much cooler. Thanks for replying.

Do the d/stairs rads get very hot if u/stairs turned off?.

The Combi side (30KW) should give 13 lpm at 40C (from mains at 7C) and will supply 2 showers if "eco" restrictors installed to give 5/6 LPM to each shower. It should supply 11.3 LPM at 45C if filling the bath.

 

[LiamIreland]

Do the d/stairs rads get very hot if u/stairs turned off?.

The Combi side (30KW) should give 13 lpm at 40C (from mains at 7C) and will supply 2 showers if "eco" restrictors installed to give 5/6 LPM to each shower. It should supply 11.3 LPM at 45C if filling the bath.

Yeah, they do get hotter downstairs if the upstairs are turned off

 

[LiamIreland]

I agree with you.....too small.

Not a great choice of installing a combi boiler for the domestic hot water side either.

Were you advised this was the way to go or did you ask for a combi.

We were advised. Thanks.

 

[John.g]

Yeah, they do get hotter downstairs if the upstairs are turned off

A bit strange that with all rads on that d/stairs are only lukewarm & u/stairs very hot, if the boiler isn't firing at 100% under these conditions then points to a rad balancing problem, if you monitor the gas meter then you will soon find out.

 

[WC1]

Possibly too small and certainly not suitable for your hot water needs but before calling another plumber the system definitely needs "balancing" as above.
Lots of youtubes on the subject. It takes a while and you must do it properly.
Once its balanced and all the rads are at approximately the same temp, you will have a better idea if its man enough.

 

[oz-plumber]

Re: Rads.
I would turn off all the rads on the first floor and then check to see if the rads on the ground floor heat up as the first floor rads do. If they do, it could be a balancing problem.
You may have to close off the lockshield valves on the first on the first floor so that the water is pushed through the ground floor rads. Not a major issue - just a system balancing issue, although this should have been done for you by the installer.
It's normal practice to balance the system through the lockshield valves.

As for the domestic hot water - in the interim, you should be able to work out the capabilities of what the system can deliver.

General:
I don't thing the boiler is big enough for your heating requirements.
I think your domestic hot water requirements are beyond the capabilities of the boiler installed.

I would contact the boiler manufacturer and have a civil conversation with them about the capabilities of their boiler in your situation.
They should tell you whether or not your / their boiler is capable of suiting your system requirements.

Depending on what the manufacturer says, you may have some recourse on the plumber that installed the system.