I want to replace my faulty 19 year old Potterton Netaheat 16/22 Gas Boiler. The replacement boiler needs to be capable of running 13 radiators (I have a 4 bedroom, 2 bathroom property). One Corgi Engineer has recommended a Baxi Solo 18 HE Condensing Boiler. Another Corgi Engineers says I require a Baxi Solo 24 HE as the Solo 18 is not up to the job. The question is, will an 18 KW boiler do the job or do I indeed need 24 KW output? Is Baxi the right choice and would you recommend it?
What Size/Model Boiler?
- Thread starter simmodave
- Start date
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You have to work out the heat loss for the house, see what output your rads will give on the lower temps the modern boilers like to run at, decide what water heating requirement/load you have, then make your decision.
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Depends what your old netaheat is set at, 16, 18, 20, 22?
I would go for a Vaillant Ecotec Plus 428 or 624 (system boiler), your engineer will then range rate it down to 22 or what ever you need upon commissioning.
You POSSIBLY could get away with an 18KW by doing what Chris said and also timing the HW and CH seperately first thing in the morning, probably the only time full demand will be required.
I would go for a Vaillant Ecotec Plus 428 or 624 (system boiler), your engineer will then range rate it down to 22 or what ever you need upon commissioning.
You POSSIBLY could get away with an 18KW by doing what Chris said and also timing the HW and CH seperately first thing in the morning, probably the only time full demand will be required.
YOU might not sir, but them of us what knows more, DO see a probable problem. 90% chance your old gas pipe is too small even for the boiler you have now.
If you can't do simple sums, and discount advice, don't bother asking.
ChrisR. It would appear that I have offended you in some way - this was never my intention! I have not discounted, and greatly appreciate the advice that I have been given. How does one work out the heat loss for a house - my 25 years in the army never taught me this (can you bridge a minefield or breach a river crossing?). Why would the pipework be too small for the boiler I have now - are you saying that the person that fitted my boiler 19 years ago did not know what he was doing!
19 years ago fitters did not have all the info available and regs to adhere to that we do today.
A lot of gas pipe sizes were 'that'll do'. The more powerful the boiler, the larger diameter gas pipe that is generally needed to enable the boiler to deliver its target power output and to conform to regulations about the pressure drop between the meter and the appliance.
In the 2 examples I cited the gas pipe would have to be sized for the maximum power of the boiler, even though it would be set lower.
The pipe size is also controlled by the length it has to run and any other gas appliances that come off it.
Your local corgi SHOULD work all this out for you.
I wouldn't know how to cross a minefield either other than drive a tank through it first and walk down its tracks
A lot of gas pipe sizes were 'that'll do'. The more powerful the boiler, the larger diameter gas pipe that is generally needed to enable the boiler to deliver its target power output and to conform to regulations about the pressure drop between the meter and the appliance.
In the 2 examples I cited the gas pipe would have to be sized for the maximum power of the boiler, even though it would be set lower.
The pipe size is also controlled by the length it has to run and any other gas appliances that come off it.
Your local corgi SHOULD work all this out for you.
I wouldn't know how to cross a minefield either other than drive a tank through it first and walk down its tracks
i would go for the 30 kw
I have a similar sized property and its just ticking over not on full blast with the capability of giving me the hot water wheen I need it
It uses more gas when its on full blast but the bath fills a third quicker so it uses the same amount of gas
try and get a boiler with a digital temp guage. Set the hot water at 47, so you dont have to run cold water into the bath and your not heating the water hotter than you need to........... saving money, no chance of scalding etc
I have a similar sized property and its just ticking over not on full blast with the capability of giving me the hot water wheen I need it
It uses more gas when its on full blast but the bath fills a third quicker so it uses the same amount of gas
try and get a boiler with a digital temp guage. Set the hot water at 47, so you dont have to run cold water into the bath and your not heating the water hotter than you need to........... saving money, no chance of scalding etc
Thanks gas4you. Now I am starting to have a better understanding of things! The Corgi fitter that has seen my system wants to install a Baxi Solo 18 HE Condensing Boiler - I guess he has worked out everything and knows what he is doing. I only started to have my doubts when another Corgi fitter (who has not seen my system) informed me that I would require the next boiler up (the Solo 24) based purely upon the amount of radiators I have. Thanks again gas4you.
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