Considering a few heating changes

[dormermike]

Hi

Current system is a open vented Y plan incorporating a Ideal Mexico 2 floor standing boiler (100k BTU), 14 rads, and a hot water cylinder in a bungalow (2300sqft).

As the head is not great the downstairs shower pressure is not great. Upstairs shower is a electric which I'd like to replace with a thermostatic valve shower.

The central heating F&E tank, hot water cylinder and cold water tank for DHW are in a room upstairs and taking up space. The hot water cylinder is a bit on the small side for our family.

The boiler is downstairs in its own room which has a bit of space next to it.

So ive been considering getting a thermal store, which would give hot water pressure for upstairs and downstairs showers, bigger stored capacity, and could go next to the boiler freeing up space currently taken up by the DHW cold water tank, hot water cylinder and F&E tank.

Spoke to a plumber and he is dead set that a combi will be a better bet and won't entertain even giving me a quote for installing a thermal store.

Got me thinking. Am I mad to consider a thermal store? Would keep existing boiler ideally as it's been very reliable.
Can a combi supply two showers and the 14 rads at the same time?

Thanks

 

[flameport]

Am I mad to consider a thermal store?

Probably.
An unvented cylinder is another option.
Neither is of any use if the incoming water supply isn't good enough.

Can a combi supply two showers and the 14 rads at the same time?

No.
A combi can typically supply one hot water outlet or heat the radiators. Not both at the same time.
Some larger ones may be able to cope with two hot water outlets if you don't mind low flow rates.
They are suitable for small properties with a single bathroom and low hot water requirements but are often fitted elsewhere as they are cheap and quick to install. As you have already found, there are persons that only install combi boilers and won't even quote for a proper system.

 

[45yearsagasman]

Are you not confusing thermal stores with unvented cylinders? Get your cold mains checked and get a company who will quote you.

 

[ianmcd]

A thermal store would replace your existing boiler, it is an unvented Domestic Hot water cylinder that you require but to do that with your existing boiler you would need to keep the F&E tank upstairs, some larger Combi boilers might be the answer to your problem and would be the cheapest option, all dependent on the water supply and how likely it is that both showers will be in use at the same time ? as for the heating at the same time unless someone is showering for half an hour at a time or more it is unlikely that you will notice any heat loss at the radiators

 

[dormermike]

Yes invented cylinder is what I was thinking.

It's a large ish property with 2 bathrooms and possibly adding a third. Don't see the point of having more than one bathroom if they can't all be used at the same time. I think with 3 women in the house it will be high probability of needing 2 at same time at some point.

Interesting we just had a new suite fitted and the gravity flow was perfectly fine before and now both the shower (bigger head) and bath are poor flow. Both are independent supplies from the water tank so I'm not sure what could be different aside from he fittings themselves reducing the flow?

 

[dormermike]

Looking at Worcester 42CDI it gives a flow of 17 litres per minute which seems pretty good

Due to the poor flow on my new shower I need to install a shower pump or get moving on the unvented cylinder. A large combi may be easier all round?

 

[Hugh Jaleak]

Be aware of the limitations of a combi. 17 litres a min is possibly achievable in certain situations, but will also depends on mains supply being capable of providing that, temp of incoming water, etc. Also if it breaks down you have nothing, heating or hot water. With 3 possible bathrooms, forget it. Unvented with immersion back up, so at least you can shower in the event of boiler breakdown.