Horstmann ChannelPlus H37XL - one channel no output?

[Hopefuldave]

I'm trying to determine next step - H37XL-controlled system not supplying hot water

Checking at the 10-way block in the airing cupboard, the line to the cylinder thermostat doesn't receive 240v, so the motorised valve doesn't open, followed by no closure of the microswitch.
Manually operating the valve (and holding open with an elastic band) with the heating on, holding the motorised valve open (elastic band again!) allows primary water to the calorifier and heating circuits and hot water eventually results!

Without the heating on, there's no 240v available (from the heating valve microswitch OR the hot water valve microswitch) to start the pump or fire up the boiler...

This looks to me like a failed relay? in the controller, for the HW channel, has anyone had one apart and repaired by replacing the relay? I'm a pretty competent electronnics tech with Some Decades experience, if that makes a difference...

Cheers, and thanks in advance!
Dave H. (the other one)

 

[CountryFan]

I have never had the opportunity or know-how to change and have always just changed a failed programmer. In the meantime, if you don’t need the heating, you could swap the wires around in the H37XL, or just put a link in from L to NO. @DP may have done what you ask.

 

[ericmark]

I have Wiser, and like the Horstmann ChannelPlus H37XL it uses a back-plate and once the unit is removed from the backplate there is no way to test it. I am lucky I also have Nest Gen 3 in parallel so I can test at that hub.

The question is it worth replacing the Horstmann ChannelPlus H37XL or would you up-grade?

I would fit a link wire on the backplate to test.