Worcester boiler CH temp issue?

[Type_901]

Experiencing an issue with a Worcester Greenstar 21i conventional boiler if anyone could help!

I have previously installed a Tado smart controls system and is all working correctly with my 3 zone s plan system (CH x2, & HW). Boiler fires from the LR (signal) when the Tado calls for heat but have noticed the boiler acting oddly now in the warmer weather where there is no calls for heat.

It looks like the boiler is trying to maintain the CH flow temperature by intermittently firing throughout the day - is this normal? Flow temp is currently set at 60c on the boiler. Have looked at the wiring in the boiler and all looks correct. The 230v supply from the fused spur is connected to L/N IN, then L/N OUT to the wiring centre, and the signal live from the zone values is connected to LR CH. This all looks correct from the Worcester wiring diagrams.

Is there potentially a setting in the boiler menus that needs to be changed? Only thing I can think of..

 

[ShaunCorbs]

Sounds like a tado issue to be as the boiler will either fire or not it’s a simple boiler

 

[gmartine]

If there's no call for heat what are your Tado hot water settings, is it on all day by default or have you managed to set up a time block?

 

[Deleted member 120897]

I would be testing the voltages back from the motorised zone valve(s) to rule any of those out, including hot water. As @ShaunCorbs says it’s a simple boiler, and will only fire up when told to do so by an external control. Could it be hot water on constant and attempting to maintain cylinder temperature? Could a link have been left in somewhere?

 

[Type_901]

Thanks for the input on this, much appreciated! All sorted now thankfully.

Got out the multimeter and started checking the wiring centre. The HW zone valve was the culprit in the end. The spring return on the actuator was sticking and keeping the relay open. I missed that the thermostat on the HW cylinder was also set to 60c so this is why the boiler kept firing to maintain cylinder temp until failing spring return eventually closed. Had a spare actuator body here so wired that in after checking the valve body was turning freely. Looks like its all sorted now!