worcester Bosch 42cdi

[Bigtree]

Hi folks, my home is currently heated by a Worcester Bosch 30si boiler and we are nearing the end of quite a large extension. Our boiler won't be 'man' enough for all of the extra rads, en-suite, utility etc and our builder has recommended an 42cdi as a replacement which will be more than capable.

Any thoughts or other alternatives?

 

[simond]

Hmmm.

I'm glad you already know the 42Cdi will be more than capable.

Exactly what qualifications has your builder got in relation to heating systems?

 

[muggles]

Sounds like a massive extension. My 4-bedroom house uses 14kW and has almost no loft insulation - I expect to be able to reduce this to 12kW when we get the insulation contractors in in a few weeks' time. If your house is really three times the size of mine, a combi is not the answer

 

[Bigtree]

Hmmm.

I'm glad you already know the 42Cdi will be more than capable.

Exactly what qualifications has your builder got in relation to heating systems?

Erm, well.....his plumber is Gas Safe, was Corgi, 25+years in the trade so I can only trust that his calculations are correct and trustworthy? What more should I expect of a tradesman?

 

[Bigtree]

Sounds like a massive extension. My 4-bedroom house uses 14kW and has almost no loft insulation - I expect to be able to reduce this to 12kW when we get the insulation contractors in in a few weeks' time. If your house is really three times the size of mine, a combi is not the answer

We are almost doubling the size of the house with the extension. 5 bed, 1 bath, 1 en-suite, 2 reception etc. Would you suggest that the flow rate on our current 30si would be sufficient?

 

[oph]

unvented cylinder or thermal store and a system boiler.

The Worcester will give you 17 litres per minute from ONE tap. More than one run then you'll still notice it. Even with a 42 cdi

 

[Bigtree]

unvented cylinder or thermal store and a system boiler.

The Worcester will give you 17 litres per minute from ONE tap. More than one run then you'll still notice it. Even with a 42 cdi

Would that mean having a hot water tank again?

at 17 lpm am I right to believe that it would be 'less' noticable than a lower flow rate?

There is never a simple answer in life is there?!!!!! lol

 

[oph]

unvented cylinder or thermal store and a system boiler.

The Worcester will give you 17 litres per minute from ONE tap. More than one run then you'll still notice it. Even with a 42 cdi

Would that mean having a hot water tank again?

at 17 lpm am I right to believe that it would be 'less' noticable than a lower flow rate?

There is never a simple answer in life is there?!!!!! lol

It does but they could go in the roof without the need for a tank in the roof to aid it as well

 

[muggles]

Sounds like a massive extension. My 4-bedroom house uses 14kW and has almost no loft insulation - I expect to be able to reduce this to 12kW when we get the insulation contractors in in a few weeks' time. If your house is really three times the size of mine, a combi is not the answer

We are almost doubling the size of the house with the extension. 5 bed, 1 bath, 1 en-suite, 2 reception etc. Would you suggest that the flow rate on our current 30si would be sufficient?

I'm suggesting that the heating capability of your existing boiler is perfectly adequate, and that you need to have a hot water cylinder installed given the expected demand on your hot water supply. A big combi like the 42CDi will be inefficient on the heating, and won't provide you with adequate hot water to run both the bathroom and the en-suite at the same time. Worst of both worlds. You'd be far better off with a 20-ish kW system boiler and a hot water cylinder, or alternatively retaining the boiler you have and connecting a cylinder to it

 

[Agile]

My five bed house manages on a 24 kW boiler.

As said your boiler is totally adequate for heating your house.

With more than one hot water outlet you need a hot water cylinder which can be heated by your current boiler.

Could it be that your builder's ever so competent plumber is just going along with the builder's desire/instruction to tell you that you need to spend more money with him?

Otherwise why would five engineers here, giving their advice for free, all tell you that all you need is a storage cylinder?

Money has a very powerful influence on advice.

Tony