To update this to help anyone else in the future, having also tried replacing the thermistors to no avail I actually removed the L / N from the controls, the boiler then sat in its 'heat' mode completely idle which helped isolate a wiring issue.
I managed to suss out that the feed from the spur...
Did you ever resolve this?
I have some similar behaviour with a 330+ boiler which is short cycling without any demand for HW/CH. It boosts flow temp from around 55 degrees for 20-30 seconds before shutting off. As temperature falls again it then repeats, pump doesn't run unless 2 ports engage...
Did you ever resolve this?
I have some similar behaviour with a 330+ boiler which is short cycling without any demand for HW/CH. It boosts flow temp from around 55 degrees for 20-30 seconds before shutting off. As temperature falls again it then repeats, pump doesn't run unless 2 ports engage...
@stem I've ruled out the PCB as a replacement doesn't change the behaviour.
Given your electrical expertise, I've noticed I do have a sticky microswitch in one of the 2 port valves which I think despite it not always causing the pump to run may be enabling the boiler to fire. Is this plausible...
The saga continues. I've concluded that this wiring fault was intentional to stop the boiler dry faulting, we have a mix of F22 Dry, F11 and rarely F25 Diff.
It now needs a regular reset but otherwise runs completely fine. There is still audible air in the flow and return after no demand for a...
To update this, a local plumber diagnosed a wiring fault. Both 2 port valves are fine.
Must have been historic or at some point something somewhere has been changed creating a permanent live to the pump.
Easiest to re-wire than to try to trace and reverse engineer.
Even the old controls see the pump running permanently, I'll get someone out to look at the motorised valve.
Unusually after restoring power to the boiler an F22 fault (Dry / Low Water) appeared which looks to have been resolved with a reset of power again.
It looks like there are 2 x 2 port.
Sorry, I should have said wireless (not wired!) thermostat!
Strangely now this morning the pump for CH seems to be running, with the display showing ‘45’. Yesterday evening having returned wiring on the WR1 to its original state it was not.
When using Tado...
Thank you!
Here’s how the original controller was wired, I’m wondering if the HW NC wire you mention is actually somewhere in the receiver in the airing cupboard by the tank / WR1.
For the time being I have reinstated terminals 1 & 3 in the WR1 and left the old wired thermostat set to 30...
I’m unsure but the original controller had separate CH and HW ‘once/twice/off’ sliders.
Do these images help identify the type of system I have?
I haven’t modified any wiring in the airing cupboard, only on the controller for the new receiver.
Thank you.
Afternoon All,
Moved home recently and installed Tado V3 to replace EMP2 timer and a WR1 / thermostat.
HW worked okay but CH didn't until I realised the WR1 receiver next to the tank was still controlling the call for heat, so from searching I've joined terminals 1+3 together in the WR1 and...