No heating only hotwater then heating works when hotwater on aswell as heating

Heardd11

The hot water works as it should and 'fires up' my boiler but there is no heating whatsoever. The thermostat appears to be working inasmuch as it seems to be sending a signal to 'fire up' my boiler but even when the boiler does make an initial attempt to work, the burner light does not continue to stay on for longer than a minute or 2. It then just flashes on/off. I've never had a problem with it supplying both the heating and hot water before. Apparantly this means its 'receiving a call for heat but is already within it's running temperature range'. By the way, I don't actually understand what this means per se, but as I've never had a problem before so don't see why it would be a problem now.

I've gone through loads and loads of items posted on the support/community pages and still cannot work out what's wrong. The only thing I've found that's incorrect so far is that the thermostat has a tick to say the EK is being used which it isn't and there's no option available to changing this.

I've reset my boiler, removed then re-added the internet bridge/receiver/thermostat...

I'd be so grateful for any help as I'm freezing

Heardd11

Put in y plan green the motor valve moves like it should no response from pump

GrilledCheese2

If this is a Tado system that was previously working then the most likely explanation is a faulty motorised valve, nothing to do with Tado. Hot water only will work even if the motorised valve has no power, it's the default state. For Heating only there's a micro switch inside the motorised valve that makes a circuit when the motor drives the valve to the heat only position. Either the motor has failed or the micro switch is broken.

Heardd11

Grilled cheese thank you for responding the port valves works there power and moves like it should and clicks but pumps not coming on David

Heardd11

It's very weird David

GrilledCheese2

This is how to test for a faulty micro switch.

1) Turn on the HW in the app (CH off). Turning the cylinder thermostat to Max should trigger the pump and boiler to run. Turning the cylinder thermostat to Min should turn the boiler off.

2) Turn on HW and set CH to 25°C in the app. Turning the cylinder thermostat to Max should energise the motorised valve and you will hear it move to the mid position. The pump and the boiler will then run. If you then turn the cylinder thermostat to the Min position you will hear the motor move the valve to the end stop and the boiler should continue to run. If the boiler stops then the micro switch has failed.

Heardd11

Okay thank you so much David

Heardd11

Noob question is micro switch on the boiler I'm guessing 3 port valve

GrilledCheese2

No, the micro switch is inside the motorised valve head.

One final check. Inside the wireless receiver make sure the wire connected to HW NC (HW OFF) has not become loose. The loss of this wire will cause a similar problem, but I guess the wire should be okay if you've previously had Tado working.

Heardd11

Micro switch has failed pump stopped and boiler shut off

Heardd11

I'm assuming it's that thank you David

Heardd11

Thank you will look David

Heardd11

Don't look loose going to have to get a new 3 port valve