Logic boiler is playing up

[rat840771]

I have a ideal Logic boiler, gravity fed system

In the evening, the thermostat is off, hot water and heating off but you can still hear the red pump in cupboard running and getting very hot. There are 2 blue thermostats ( one flow and other return?) in the past if i move this lever across you hear it shut the system down. But last night this made no difference.

The boiler is also running and showing status C and not 0

So last night i have to resort to cutting the power at the switch.

Any ideas before i call a plumber.

thanks

[Andehh]

Any chance you can post a few annotated pictures of said problem? Might help reveal which parts you are talking about.

[Alucidnation]

Easy enough to google.

[Alrey87]

The blue things are actuators not thermostats. One of them is faulty and causing a constant 240v supply to the boiler (switch inside actuator has stuck) hence it always runs. Or the mechanical valve which the actuator operates is seized stopping the actuator returning to "off" position and turning off its internal switch.

[rat840771]

Yes, this does seem to make sense.

Is there any way you can free them up?

Today the heating is on but the thermostat and timer is set to off!

I pushed the 'lower' actuator lever across to try and shut it off and it has appeared to have locked into this position.

As you can tell i am no plumber or heating expert...i'd better call the plumber.

Alrey87 said:

The blue things are actuators not thermostats. One of them is faulty and causing a constant 240v supply to the boiler (switch inside actuator has stuck) hence it always runs. Or the mechanical valve which the actuator operates is seized stopping the actuator returning to "off" position and turning off its internal switch.

[Alrey87]

Easy job but actuator probably needs replacing. If it's blue it's probably an old Drayton / British Gas one. You can push button on side of it and pull it off the valve then check if the spindle on the valve moves freely. If you do t while the power is on and pump 'stuck' on then when you pull the offending one off the actuator will spring back and the pump will stop. If the actuator is faulty internally then pump will continue to run and a new actuator will need wiring in.

[rat840771]

Thanks for the info, yes they are blue.

There are 2, i have been going to the one 'higher up' and moving the actuator across and you hear the pump stop, but you can watch the actuator trying to move back across, but the other day this didn't seem to help so i tried the lower one and moved it across and locked it. Now i can't seem to unlock it. Boiler and pump wouldn't stop running, so i had to turn off the system at switch.

Turned boiler back on today and now heating is running with stat and timer off.

will have a look later.

cheers