Evohome setup to incorporate a thermal store unit

[mtmcgavock]

My current system is an old gas boiler for heating and DMH. Working through a three-way valve. Evohome controls it all, sending messages when heat is needed or not. DHW is similarly set up with a strapped on thermostat talking to its base which in turn talks to its own relay. All works, no real problems. Pleased with it.

Ahead though is a growing need to change the boiler. It’s getting old. A vented Thermal Store appeals because it gives DHW at mains pressure. No pumps for the showers as I have at present. Also they have some future proofing in that they can be used with alternative power sources. It also means I can get rid of the tanks in the loft and create more space for stuff - others will call it sh.t but then what they call “stuff” I would call sh.t.

My current thinking is to install the DHW internal thermostat that works with Evohome (if that is possible) and possibly with time controls set up when it is to operate. With some Thermal Stores it seems you can. But perhaps better ignored and let the boiler just fire up when it senses the store needs a top up. I don’t know if that will work or prove expensive to run and am looking into that. Our DHW is only heated for 30 minutes in the morning and 30 in the evening.

You'd be better with an Unvented HW cylinder than a thermal store, especially if you've only got one heat source. You'd have to heat the store to a high temperature, for longer periods than you do now. An Unvented cylinder you could probably get away with what you heat it now.

[G4RHL]

Installing an unvented cylinder may not be practical as I am advised radical changes to the incoming cold water feed are needed but none are needed with a vented cylinder it being a simpler alternative. I note that Worcester Bosch have stopped making unvented cylinders.

[mtmcgavock]

Installing an unvented cylinder may not be practical as I am advised radical changes to the incoming cold water feed are needed but none are needed with a vented cylinder it being a simpler alternative. I note that Worcester Bosch have stopped making unvented cylinders.

Isn’t going to be any different for a thermal store? It’s still mains pressure for the HW...

They’re just a bad idea IMO, ripped so many out over the years. I’d have a combi before a thermal store.

[G4RHL]

Yes it is, different that is. I understand unvented needs the cold water main taking straight to it and that means work on the cold water taps. Not practical in my case.The vented does not have this problem. On the latter I am100% certain but not so sure on the former. As for viability it seems they have come a long way in the last few years and there are plenty of them being made. I first came across them with a friend who had a vented thermal store. He inherited it when he bought his property but found it excellent. More recent articles about them are much more positive than ones of 10 years ago. The unvented is not cheap to install and has cost issues. My mind is not made up though I am just looking at all permutations including electric - a dry system.

[mtmcgavock]

Yes it is, different that is. I understand unvented needs the cold water main taking straight to it and that means work on the cold water taps. Not practical in my case.The vented does not have this problem. On the latter I am100% certain but not so sure on the former. As for viability it seems they have come a long way in the last few years and there are plenty of them being made. I first came across them with a friend who had a vented thermal store. He inherited it when he bought his property but found it excellent. More recent articles about them are much more positive than ones of 10 years ago. The unvented is not cheap to install and has cost issues. My mind is not made up though I am just looking at all permutations including electric - a dry system.

The vented section is the store only, the HW is supplied by mains pressure that runs through a coil.

Only want round it would be to fit a new vented cylinder like I assume you have now.