CH relay module switching bolier on intermittently?

[blackwaterpfc]

I have a Honeywell wireless room 'stat HCW80 and an associated relay module HC60NG, I have done the teach in and the stat and module communicate OK, the green LED on the relay module goes off when the stat is turned down below ambient and on when it's raised above it, the LED on the stat goes on and then the green LED on the relay module comes on OK.

But quite often the boiler doesn't kick in, sometimes it does but more often it doesn't, especially first thing.

Is there anything I can check myself or do I need to call in a spaecialist?

I have a reasonable level of electrical knowledge, multimeters etc/

Thanks
Steve

 

[45yearsagasman]

The boiler model would help, then we could see the wiring connections.

 

[blackwaterpfc]

The boiler model would help, then we could see the wiring connections.

Forgot that bit. sorry.

The boiler is a potterton promax SL and the timer is a drayton lifestyle LP522 dual channel unit

Thanks

 

[45yearsagasman]

You probably have some external controls like zone valves near the cylinder.
I would be checking there to ensure that these controls are working.
The boiler only requires a switched live for it to fire. When it is in a fault condition, check (be careful) that is receiving a signal to the SL terminal.

 

[blackwaterpfc]

You probably have some external controls like zone valves near the cylinder.
I would be checking there to ensure that these controls are working.
The boiler only requires a switched live for it to fire. When it is in a fault condition, check (be careful) that is receiving a signal to the SL terminal.

Is the zone valve a "drayton mid position actuator MA1"? How do I go about checking that?
Also how do i check the switched live terminal? I assume I need to remove the boiler case to get to the terminals.
Steve

 

[D_Hailsham]

Does the supply to the HC60NG L terminal come from the CH ON terminal of the LP522?