Re: [OT] Thermal Stores for hot water/heating

[Mal Lansell <mal@xxxxxxxxxxx>]

They're not very common, so I guess most plumbers won't know too much
about them.
I had a flat once that had a thermal store - it worked great.  You get
mains pressure hot water without the crap performance and constant
cycling every time you turn the tap on.

You can get vented thermal stores - there's no need for them to be
sealed and pressurized (except to earn the heaitng trade their annual
maintenance fee, as you mention).  The vented ones don't need building
control approval either.

The calcification issue sounds like B.S to me.  The water flowing
through the boiler is not being constantly refreshed - it's no more
likely to calcify than in a regular hot water tank system, and you can
add all the inhibitors etc you want.

Mal


Jonathan Shaw wrote:

> I read a lot about hot water cylinders before talking to plumbers and
> decided that with underfloor heating + radiators & a condensing
> boiler that a thermal store was the best option as theory is that
> even when heating the house (rather than water) the themal mass of
> the heatstore gives the boiler something to work on and
> prevents/reduces boiler cycling/ inefficiency associated with
> condensing boilers and zoned heating whre only one room may be
> calling for heat.
>
> None of the (getting on for 10) plumbers I have spoken to think this
> is a good idea. All generally vague reasons that seem to centre
> on "I fit what I know" rather than listening to customer; oh
and the
> annual service for the pressure relief valves needed for unvented
> cylinders, nice litle earner. One suggested in hardwater areas the
> heat exchanger would calcify, but Googling doesn't seem to back this
> up. Naturally eh suppliers (Chelmerheating, Nu-heat, Gledhill) all
> deny this is a problem.
>
> Are there any heating engineers on the list that can offer advice?
> Or anyone with a thermal store in a hardwater area?
>
> TIA
> Jon
>
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