Hot water zone will not fire the boiler independently

aw · 28-10-2017 8:00pm #1

Hi there.
We currently Have a Horstmann Channelplus H37XL timer with three zones (Upstairs, Downstairs heat and Separate hot water).

Upstairs and Downstairs Zones work fine, fire the boiler as required.
The hot water zone will not fire the boiler independently, however.
It will work and heat the water when one or other of the other zones fire first, but will not fire on its own.

I had a similar system in a previous house where the water zone worked independently.

Is is possible to tell if something is set up incorrectly or broken on my system?

Wearb · 28-10-2017 8:25pm

Check that the thermostat for the hot water is turned up enough. Otherwise it could be a faulty zone valve, stat or controller.

Bscan86 · 29-10-2017 2:00pm

If it has never worked independently then I would imagine 1 or both of the auxiliary switch cables of the hot water zone valve are not connected or broken.

aw · 30-10-2017 8:33pm

Had a closer look.
There are 2 motorised valves on the system which work fine. One for Zone 1 and one for Zone 2.
The third zone for hot water does not have a motorised valve. There is no external thermostat on the cylinder, either.

Checked with my neighbour and his has been plumbed the same.

Is this how it should be? I would have assumed that for the system to be done right, there should be a separate third valve.

Would this be relatively straightforward to sort?

phobia2011 · 30-10-2017 9:51pm

Do you have a stat on wall upstairs and downstairs?

aw · 30-10-2017 9:53pm

Yes, Robus stat both up and down.

Bscan86 · 30-10-2017 10:43pm

Is there a motorised valve in the same room as the hot water cylinder?

aw · 30-10-2017 11:07pm

Yes. One valve upstairs beside cylinder. One downstairs near boiler.

Bscan86 · 15-11-2017 6:46pm

aw wrote:

Yes. One valve upstairs beside cylinder. One downstairs near boiler.

Right now I'm not a plumber but I'd imagine the feed side of that M.V. is coming directly from the boiler. If so you could "T" off the feed side, add another M.V. for water which could be controlled by a timeclock via tankstat.

aw · 15-11-2017 7:49pm

Bscan86 wrote: »

Right now I'm not a plumber but I'd imagine the feed side of that M.V. is coming directly from the boiler. If so you could "T" off the feed side, add another M.V. for water which could be controlled by a timeclock via tankstat.

Thanks for that, I really appreciate the insight.

Bscan86 · 16-11-2017 10:19pm

aw wrote:

Thanks for that, I really appreciate the insight.

No worries, happy to help, it would be best to consult a plumber on the issue, then if all is good ask a spark about looking to see if there's a spare live core coming from the time clock to the junction box in the hot press which would act as the feed to the tankstat. If there is a spare core then you're laughing otherwise it could be bit more awkward.

Hot water zone will not fire the boiler independently

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