Tado extension relay click

Neil

Evening all. Have had my Tado set up for 3 years now with no issues. Extension kit, hallway thermostat and a few TRV’s.
My boiler won’t fire at the minute and I’m wondering if it’s the system valves that are causing the issue, or the extension kit.
It would be odd for both the hot water and heating valves to fail simultaneously. But they are not motoring to the open position and boiler doesn’t fire.

However. I’m trying to think of the extension kit just clicks when going on, but not when turning off?

I am getting the click on for both heating and hot water, but no click off. I’ve never paid much attention but I have a feeling it normally clicks off too?

I’m not at home and trying to fault find with my wife over FaceTime. Not ideal. I know.

I’m leaning towards the system valves, but the fact the extension kit relay isn’t clicking off is throwing me.

I suppose my query is… should I hear an off click from extension kit.

I’m not electrically minded but wondering if the system valves don’t move to meet the micro switch in the on position, then possibly the click off will never be heard (that may be total tripe…) from the extension kit.

wateroakley

Our HW relay on the wireless receiver 'clicks' when switching ON and when switching OFF. Are the receiver lights ON or OFF? If the receiver lights are ON and neither valve opens to fire up the boiler, can SWMBO move the lever on the CH or HW zone valve to the right? This is the manually override and should bring the boiler ON? It is not unknown for a failed motorised valve head to blow the 3A fuse for the boiler, which would exhibit as no HW and no CH.

Your last para is incorrect, sorry. The logic sequence: Tado App ON>Tado>wireless receiver (lights ON and microswitch 'click')>zone valve head motor moves (might hear a faint whirr as the mechanism moves)>valve motor head switch ON (silent)> boiler/pump ON.

Tado App OFF>Tado>wireless receiver (lights OFF and microswitch 'click')>zone valve motor released>valve motor head switch OFF (silent)> boiler/pump OFF.

Neil

Thanks for the reply wateroakley.

SWMBO has moved the valves. I’m not sure how far. She says it’s all the way. She’s held it there for a minute or so but boiler doesn’t fire.
They spring return when released.

I have the extension kit (add on) so only one light in the centre of the unit. It’s pulsing as it normally does.

I’ve replaced the motorised valve actuator previously for hot water so I’m fairly used to how it normally fires the boiler. It’s the fact both valves have failed together. So maybe your fuse suggestion is bang on.

When it’s operating fine, the app signals on. The relay can be heard clicking on extension kit then the motor on valve moves. The boiler fires a few seconds later. As you said. I seem to remember it clicking when demanded off. Then valve closes and boiler goes off. The extension kit doesn’t click currently when I set it to off on the app.

If it was just one valve not actuating open, I’d be convinced it’s the motor on the valve. Both going at once has me stumped. But coincidences do happen I suppose.

If the fuse on the boiler blows does this stop power going to the valves? I just assumed power was fed to them through the controller (extension kit)

I’ve been happy to wire in new valve actuators, but no idea on the circuit set up.

Also, if the boiler fuse was blown, would the display not be affected? It seems to be looking normal in every way. Display etc is on.

wateroakley

Always worth trying a 'tap' on the receiver in case the microswitch is stuck?

If the boiler doesn't fire up when SWMBO moves the zone valve lever (spring-loaded) fully to the right, that suggests the problem is NOT the Tado parts. The only part of the system the valve head controls is the valve itself, the microswitch and then power to the boiler? Older valves can become sticky or siezed, preventing the microswitch mechanism from working properly and/or burning out the motor. Unusual, but not the first time I've replaced two siezed zone valves of the same vintage inside a week.

Hope you can get it sorted for SWMBO.

Neil

Hi again. Sorry for delay. Managed to get it sorted last week by resetting the extension kit (button on top - hold til light goes off)
Seems to have done the trick. For a week. And same thing happened. Nothing gets boiler to fire.
Tried the reset on extension kit but didn’t work this time. Actually removed it off the wall and refitted it. Powered up again and worked.
I have a sneaky feeling the relays in the extension kit are playing up.
I checked when I last bought it. 2019. Looked for a new one and it seems it’s discontinued. Would mean buying the new wireless extension kit. However. A little put off as I’ve seen in this forum that the instructions don’t have a transition from old extension kit to new with regard to different wiring.