One zone failing to heat rads: controller or valve?

[Kester_holmes]

Programmer - live straight to the the valve and SL back to call the boiler, system will rely on boiler stat to modulate, not very efficient especially these day though relatively easy to upgrade.

There is also a thermostat on the heat store/ storage cylinder.

Interested in what upgrades you recommend: do you mean WiFi trvs or room thermostats or summat else? It’s oil boiler as no mains gas, so fairly costly.

We try and minimise use of the heating full stop, by 3 short time slots , rather than on all day, and use log burner with whatever wood we can scavenge.

Cheers

 

[Madrab]

The standard way would be to fit wired stats, one in each zone back to a wiring centre then interlink them with their respective 2 port valve > boiler. As long as the cable can be run effectively then that's the easiest way to do it.

Alternatively, you can use wireless stats but there still needs to be a hard wire between the receiver and the 2 port valve.

Wireless TRV's can be used but they would need to be interlinked through a central programmer/controller or a hub then back to a controller to the boiler to enable full control, can be quite expensive and need to become familiar with smart controls.

 

[Kester_holmes]

It was the grey wires connected to the pump live, and one of the valves was never making that live/never coming on.

It was definitely the valve head that failed. Think it’s seeping much not amount of water and seized up the motor bit over summer.

It confused me that I think the replacement that I bought off eBay was faulty, but the one valve now works on either zone, so just need to source a working replacement for the one zone.

 

[Madrab]

It was the grey wires connected to the pump live, and one of the valves was never making that live/never coming on.

The grey wire should be a permanent live and should get that from the wiring centre/FCU. When a call for heat the valve is energised by a live from the programmer to it's brown wire, the valve opens, it then hits an internal microswitch and that sends the grey live down the orange switched live to the boiler. Ideally the pump should be run from the boiler so the boiler can manage any required overrun.

John Turnbull