New hot water and heating boiler

[pee1]

The OP has a quote for a Vaillant ecoTEC plus 637 which is a system boiler.

Any thoughts on this quote???

 

[denso13]

Any thoughts on this quote???

It isn't too bad but the only way to tell is to get a few more quotes.

Don't think I'd be happy paying so much up front though.

 

[fixitflav]

The OP has a quote for a Vaillant ecoTEC plus 637 which is a system boiler.

OK my bad. I didn't notice it had changed from 638 to 637.

 

[fixitflav]

I've decided on a boiler and cylinder.

Do you have any advice on this?

3 bathrooms 18 rads.

37kW is probably grossly oversized. What output is the current boiler? Does it cope with the demand? As cross thread said in #2, best to do a heat loss calculation.

 

[pee1]

37kW is probably grossly oversized. What output is the current boiler? Does it cope with the demand? As cross thread said in #2, best to do a heat loss calculation.

Currently I think its 30kw.

Would prefer a more the capable boiler to heat 6 bedrooms over 3 floors.

 

[fixitflav]

Currently I think its 30kw.

Would prefer a more the capable boiler to heat 6 bedrooms over 3 floors.

Does 30kW seem borderline? It still seems high to me, though obviously houses vary.

 

[JohnD]

Currently I think its 30kw.

Would prefer a more the capable boiler to heat 6 bedrooms over 3 floors.

you can carry out a heat loss calculation for the house if you want. It is extremely unlikely to need as much as 30kW

A sensibility check:

In frosty weather, does your existing boiler run continuously, at full power, but is unable to keep all the radiators fully hot, with the result that the house is cold? And does your gas meter confirm that it is burning 30kWh of gas an hour? (there are about 11kWh in a cubic metre of gas so this will be almost 3metres an hour and cost you about 33p an hour at my prices last December; probably more today)

if so, it may be undersized

 

[snb]

If you have 6 bedrooms over 3 floors then i wouldn't be using a system boiler, or if i was i would possibly using a low loss header as the resistance across the giannoni exchanger is very restrictive. That will also be the problem with your current boiler although the resistance across the exchanger is much less. If you do go for a boiler that is too big you can have problems with cycling

 

[pee1]

Work in progress
Any comments/suggestions?