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Feb 8, 2020
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I am contemplating of having 2 domestic boilers (35-40 kW each) for the communal heating (no hot water) of a 12-flat residential block that would replace a 50-year old 68kW boiler for the heating.

The waranties for domestic boilers are much longer than commercial boilers. For example, a domestic Worcester Bosch boiler can have a waranty of up to 12-14 years, assuming an authorized installer installs them and the circulating water meets certain metrics.

My plumber tells me that domestic boilers last longer because they get less hot than commercial ones which are bigger, and for that reason they last longer. Is this true?

Thanks
 
Commercial boilers don't run any hotter but they run on full load or near for far longer than Domestic boilers would.

As GasMK1 said parts cost far more, probably because individual boilers are built in far less numbers due to the greater range of Commercial heating compared to Domestic.

As to why the Warranty is greater on Domestic, I'd say partly market forces, i.e competition from others, partly reliability due to lower production and development of Commercial boilers.

I used to do Commercial gas, but now retired, so that makes the remaining gas engineers even more valuable.. 🙂
 
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And as Per Shaun, whatever boilers you are planning check with the manufacturer about their use for multiple flats.

I'd suggest you contact the manufacturer yourself and get an email confirmation from them if it is O.K
 
And as Per Shaun, whatever boilers you are planning check with the manufacturer about their use for multiple flats.

I'd suggest you contact the manufacturer yourself and get an email confirmation from them if it is O.K
good idea, especially with email conformation
 
Even domestic boiler in a small commercial environment, say a small office, don’t qualify for the warranties offered by the manufacturers if you check the t&c’s
 
Houses in Multiple Occupation (student homes) may or may not be Commercial for the purposes of Property tax or other considerations but from the boiler use it's the Manufacturers determination that matters.
Individual manufacturers may have different views.

But I'd expect to see lots of posts re manufacturers rejecting warranty claims on HMO if they did consider them Commercial as I doubt many people fit Commercial rated boilers in them.
 
Commercial boilers don't run any hotter but they run on full load or near for far longer than Domestic boilers would.

As GasMK1 said parts cost far more, probably because individual boilers are built in far less numbers due to the greater range of Commercial heating compared to Domestic.

As to why the Warranty is greater on Domestic, I'd say partly market forces, i.e competition from others, partly reliability due to lower production and development of Commercial boilers.

I used to do Commercial gas, but now retired, so that makes the remaining gas engineers even more valuable.. 🙂

I’d be interested to see how many boiler warranties are actually honoured, most (all?) seem to have installation requirements, servicing requirements and exclusion like hard water areas and exclude fair wear and tear.

I suspect by the time you get to 5 years there aren’t many appliances that haven’t invalidated the warranty in one way or another.
 

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