Thermal storage system or OSO?. 2 firms 2 proposals.

[maggeo13]

Hi,
We have a blank canvas for water heating with a 1930's extended end terrace - the requirement is for 2 bathrooms, 12 radiators and DHW. We haven't laid the floors yet so there is easy access for pipe laying.

We have one quote for -
Grants Vortex 70-90 Condensing boiler, thermal storage cylinder, myson radiators, Danfoss valves, etc. £5700 + VAT.

We haven't got the second quote yet but the plumber is talking about an "ordinary" boiler with an OSO cylinder. Both are experienced and reputable firms. We have loads of water pressure and flow.

My head is spinning after reading the forums, etc but it seems to me that these are two quite different systems?.

Could any kind person run briefly through the pros and cons, and any reason why the different proposals?

We would like to have plenty hot water for baths and mains pressure showers.

 

[baxpoti]

Have a look at the promax store 150i

 

[simond]

Is that an oil boiler? Promax sounds like a gas to me.

The differences between a thermal store and an unvented cylinder have been debated ad infinitum here. Tempers have been raised and battles fought.

One heatstore fanatic has had to change his user name 4 times now due to the flak.

There is no right or wrong answer, but in my own personal opinion I would not be influenced by stories of unvented cylinders exploding. This is virtually unknown and you would be far more likely to win the lottery.

You may prefer to look at a Daikin or Mitsubishi air source heat pump, which use unvented/heatstores, if the house is reasonably well insulated. Oil prices are on the way up again.

 

[maggeo13]

Thanks simond, and yes I've gone squinty eyed looking at all the opposing postings in the forums!.
I'm just wondering why the two suggestions for systems appear to be so different, is it just the personal preferences of the firms/best profit margins or what?.
And yes it's an oil fired system we're after.

 

[simond]

Profit margins are generally consistent across all products. Most of us buy in at the going rate and add a fixed percentage.

So recommendations are based on experience and other factors such as installation location (eg: cellar or loft) and what the customer wants from the system. Heatstores are useful in cellars or dual/multi fuel sources for example.

I fit either depending on the application. Someone who has seen your property and discussed your requirements will always be able to make a better call than me.

 

[AlanE]

What 'ordinary' boiler was suggested? Hard to make comparisons without knowing what one is comparing boiler wise.

Another factor to take into account is that the first mentioned installer might not have an unvented ticket so his suggestion might be based on that.

Provided sufficient pressure and flow (loads of flow and pressure doesn't really give an indication of what each actually is). I would perhaps prefer the unvented route BUT bear in mind I have no idea of available space, property size or water useage. All could have a bearing on final choices.