New home woes with heating

[newcastle phill]

The only problem you face if you intend to challenge their work is ultimately this is what you will need - a professional report from a building services expert.
If you disclose your source of expertise is a general plumbing forum it wont further your cause.

 

[Sg1973]

I guess the feedback on here so far suggests it is inadequate but I wouldn't use a general forum response to go head to head with the builder. I will seek a professional and am. If I can't achieve that via a professional on this forum, then I will need to go elsewhere.

 

[Sg1973]

Just thought I'd post the latest here. The heating/plumbing engineer I hired came to view my house yesterday. He confirmed all my suspicions. The house just doesn't get warm. He said the radiators were the smallest he'd seen on a new build. I'll get a survey report from him to take to the builders, and I suspect court thereafter. He is recommending doubling the radiator, and hence, boiler size.

Got some good advice from citizens advice too on the steps to follow.

Will come back to let you all know how it goes.

 

[stevetheplumber]

Just thought I'd post the latest here. The heating/plumbing engineer I hired came to view my house yesterday. He confirmed all my suspicions. The house just doesn't get warm. He said the radiators were the smallest he'd seen on a new build. I'll get a survey report from him to take to the builders, and I suspect court thereafter. He is recommending doubling the radiator, and hence, boiler size.


Got some good advice from citizens advice too on the steps to follow.

Will come back to let you all know how it goes.

thanks for the update we would appreciate hearing the outcome of this

 

[Sg1973]

So after posting a pre (court) action letter yesterday, the builder contacted me this afternoon. He'd been on the phone to Myson's technical director (apparently) regarding the heat loss calcs and system design they were employed to do. Myson stand by their calcs but are coming to my house to see what's not working with their own eyes.

However, I checked their website and there's something odd. You can use an online tool of theirs to give you radiator recommendations. In other words, an online heat loss calculator. After trying many others online, my 5x3x2.5m room with two external walls and a 2.2m2 window, I usually get around 5000BTU as the heat loss. Myson's calcs show a heat loss of 785 watts or 942 after allowing for a heat up factor. That's about 3200 BTU.

Is this because a lot of heat loss calculators don't allow for current building standards?

If anyone can point me in the direction of the best site for heat loss calcs, I'd appreciate it. If necessary I could always hire someone to do the calcs for me.

Cheers

Sean

 

[newcastle phill]

If its a new build fabric heat loss is a lot less than older houses for sure.

 

[chris watkins]

You can't beat full manual calculations although it takes a bit of time IMHO.

Any fabric heatloss calc whether manual or on a computer must include the selection of all the fabric parts i.e. walls, floor, ceiling, windows & doors construction including the levels of insulation.
They also need to take account of what is on the other side temperature wise & then there is the heat lost through ventilation which varies depending on chimneys & extractor fans etc.

Most freebies just give a ruff & ready idea only for replacement with results that can vary greatly.

Whoever does them will need to establish the construction make-up of the house & use this in the calculations to establish the design loading there are still some variable that they could come up with such as the designed outside temperature (-1 or -3deg C for most parts of the counter), the location exposure & heat up allowance, as you mentioned etc.

All of this is set out in a very good book that a lot of the better engineers refer to called the "Domestic Heating Design Guide", not sure what the latest edition is, mine is 2013, but maybe worth the £28 or so cost.

 

[Sg1973]

So. Myson's technical director came today with someone from the builder. They absolutely stood behind their calcs and system. However, it transpired that there was a weather compensator fitted, limiting the central heating water temp to less than 60 degrees. They agreed to remove this (a quick job) and it has unleashed the full power. 80 degrees showing now on the boiler and the house is considerably warmer. Looks like they might have to remove them from all houses on the estate as it's not just me complaining.

Any other experience of weather compensators? Is this normal??

 

[newcastle phill]

Good result

 

[chris watkins]

So. Myson's technical director came today with someone from the builder. They absolutely stood behind their calcs and system. However, it transpired that there was a weather compensator fitted, limiting the central heating water temp to less than 60 degrees. They agreed to remove this (a quick job) and it has unleashed the full power. 80 degrees showing now on the boiler and the house is considerably warmer. Looks like they might have to remove them from all houses on the estate as it's not just me complaining.

Any other experience of weather compensators? Is this normal??

Weather Compensation is very good at saving you money in fuel cost and running your boiler at 80C is not the most efficient.

Some one has still mucked up the designs I feel, least ways it would suggest it was neither commissioned nor handed overt you correctly.

Was there a users guide that you did not read?

 

[Sg1973]

I was told to keep the boiler at max. But didn't know it had a weather compensator. The myson guy was very difficult to deal with, citing British standards and standing behind his own design. He reckoned removing the weather compensator would add £2.50 to the annual costs. Don't know if I believe this. But without this extra heat the radiators simply weren't getting hot enough.

I'm inclined to agree that their calcs weren't right somewhere but think it would be a real challenge to mount to say they're wrong.

 

[chris watkins]

I was told to keep the boiler at max. But didn't know it had a weather compensator. The myson guy was very difficult to deal with, citing British standards and standing behind his own design. He reckoned removing the weather compensator would add £2.50 to the annual costs. Don't know if I believe this. But without this extra heat the radiators simply weren't getting hot enough.

I'm inclined to agree that their calcs weren't right somewhere but think it would be a real challenge to mount to say they're wrong.

Which is why Sean in post 4 I suggested that --
"First thing is to request a copy of the heat loss calculations & rad sizing from the builder/main contractor."
That way you would have the figures they used & could challenge them.

If the Rads were sized correctly you could run your boiler at a much lower the temperature & still be nice & warm.