Is boiler underspec?

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That might be the problem.
Ok

Was your old boiler also set at 55C?
60C

Are you heating the water at the same time?
No.
 
Your house will heat faster if you turn the boiler up. But it might be a bit less efficient.

Is the boiler temperature displayed in numbers, or is there just a dial?

How powerful was your old boiler?

And finally! What is your new boiler model?

EDIT: it will only heat faster if your boiler has enough power. This might help determine that.
 
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Were any radiators replaced when the boiler was installed?
No

Have you tried not heating the whole house? (if you don't have any modern control gear, just turn off 2 or 3 less needed radiators (usually bedrooms) at the start of a heating period, see if/how quickly the heated areas achieve temperature.
Some of the rads have been turned off so not heating the whole house/

EDIT Did your previous quotes include any heatloss calcs for the house?
No

EDIT 2- This is a problem with heating grants- you the end user get little or no say in what boiler is installed- you'll get the cheapest or whatever the installer had kicking about that's close enough.

Yes thought as much. But if it is not fit for purpose, surely fitter has to accommodate?
 
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Your house will heat faster if you turn the boiler up. But it might be a bit less efficient.
Ok I am testing now.

Is the boiler temperature displayed in numbers, or is there just a dial?
I have a Google Nest, but all seenm to work correctly as I have another temp thermostat next to it

How powerful was your old boiler?
Was a Potterton Profile need to check model

And finally! What is your new boiler model?

Worcester Bosch Greenstar 18Ri​

 
I'd suggest you turn up the outlet temperature of the boiler. On the basis that your boiler is a condensing model (it should be) the figure of 55 is reckoned to be the latent heat recovery temperature on the return from the radiators, so your installer probably set things up incorrectly.
If the radiator delta-T (the difference between the temperature entering them and that leaving them) is around 15 to 20 degrees then the boiler will still be performing 'efficiently' with an outlet set temperature of say 70 degrees. Yes, it will burn a bit more gas to get up to this temperature but it will heat up the house faster and hence satisfy the room thermostat setting. I take it your thermostat is an analogue type rather than a simple ON-OFF. If the latter then you need to get this changed to improve boiler efficiency and hence reduce gas consumption.
 
Did Worcester visit? Did they do a heat loss calculation? Do you operate the heating on a timed ON/OFF schedule? Does your disability mean you are house bound?
 

Worcester Bosch Greenstar 18Ri​


I've just thought of the obvious, though. If you turn the boiler temperature up, it will only heat the house faster, if the boiler has actually has enough power. But turning it to 70C will be a good test to find out if it has the power. I can only see a dial in the manual, no actual temperature in numbers?
 
I have a Google Nest, but all seenm to work correctly as I have another temp thermostat next to it

I'm trying not to overload you with questions. But I am wondering whether the problem could be down to the thermostat(s) cutting the boiler off. Modern thermostats can work in ways which are difficult to understand. What temperature is the thermostat set to?
 
Assuming 45C return (with 55C flowtemp) & a required room temperature of 20C then those rads will only emit 51% output than a design 50deg rad which would require ~ 75C boiler temp to give a return of 65C and full rated output
 
Assuming 45C return (with 55C flowtemp) & a required room temperature of 20C then those rads will only emit 51% output than a design 50deg rad which would require ~ 75C boiler temp to give a return of 65C and full rated output
Are you saying the boiler should be adjusted from 55C to 75C?

I did another test, and the heating will only get as far as 19C. I placed the temp reader in various locations of the house.
 
That temperature could probably be increased, but the weather is not presently all that cold outside yet.

Is the boiler running near continuously when there is a demand for heat?
The heating never reached above 19C despite being set to say 24C. The old boiler used to heat the house very quickly and alot higher than 19c
 
I'm trying not to overload you with questions. But I am wondering whether the problem could be down to the thermostat(s) cutting the boiler off. Modern thermostats can work in ways which are difficult to understand. What temperature is the thermostat set to?
Possible. I need to go back to the heating engineer again...
 
Assuming this was installed after June 2022, a full room by room heat loss survey should have been carried out in order to comply with Building Regulations prior to specifying the new boiler
 

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