Use UFH to store heat?

legoman62

zeupater wrote: »

Hi

Yes, it should either have 1 x 3-port motorised valve, or 2 x 2-port ones, depending on the circuit ... a 3 port setup allows heating of house or water, not both at the same time & the 2 port setup allows either or both, but neither are designed to have the DHW cylinder provide heat to the radiators ... a heat-bank (as used with heatpumps etc) does do this, but they're normally much larger than a standard cylinder, so you'd certainly know if you had one!

HTH
Z

Surely the 3 port valves options are 1 hot water, 2 central heating or 3 both?:D

zeupater

legoman62 wrote: »

Surely the 3 port valves options are 1 hot water, 2 central heating or 3 both?:D

Hi

The way I understand it is that (from a valve flow point of view) there's 1 in & 2 out on a 'T' shaped valve (ie 3 Port) ... one of the outs is naturally open, the other closed & the synchro-motor turns the valve and reverses this ... the control system operates on a priority basis - when there's a call for both, do you want hot water or hot radiators first ...

HTH
Z

legoman62

https://www.honeywelluk.com/documents/All/pdf/975.pdf

Does this show the operation of a 3 port valve?:D

zeupater

legoman62 wrote: »

https://www.honeywelluk.com/documents/All/pdf/975.pdf

Does this show the operation of a 3 port valve?:D

Hi

That sheet certainly does show a 3 port, although it is classified a 3-port 'mid position' valve (V4073) as opposed to the Honeywell V4044 range of 3 port valves I was describing ....

I have no idea what setup wobblydeb has, 2 port, 3 port or 3 port mid position, but whichever is in place doesn't really matter for four pretty pressing & relevant reasons ...

(i) the pump/boiler control system would likely need to be addressed to do what has been described
(ii) the DHW cylinder isn't really designed to do what has been described (coil at bottom!)
(iii) with a multi-coil cylinder & complex control system, there would still likely be no DHW!
(iv) unless there's a massive PV array, there'll be little benefit from even considering it as an option for space heating ...

A more straightforward solution would be to use proportional diversion to heat the DHW and have a secondary diversion to a basic electric oil radiator, in which case at least the heat could be targetted to a specific area! ....

HTH
Z

lstar337

zeupater wrote: »

Hi

Yes, it will (/can) work, but at the time of year you want heating it'll make little/no difference ...

Certainly in the case of PV.

It makes a phenomenal difference using the sun direct though.

I have south facing patio doors in the lounge and a solid concrete floor. Even though it was -4C outside yesterday it was 26C in my lounge. The gas central heating didn't come on all day because I opened up the doors to spread the heat around.

I love free heat days like that! :D