Problem Myson Apollo 30B Controller 30K BTU

[Doc Lenny]

Hi all

I have an Myson Apollo 30B Boiler system. I have just replaced the Water Pump on my heating system after it has been firing up, boiling the water and then shutting down. This has solved this problem but now the controller unit is not responding when I turn the dial or when I change it to OFF on the HW/CH - HW switch (it stays fired up). It does repond to Hi and Lo - firing up normally. I suspect a I need a new controller but when the boiler is fired up on High a strange loud clicking sound comes from the Gas valve cover.

Any Ideas?

And will the Honeywell ST6200A controller work with my setup?

Thanks

 

[ChrisR]

Programmer (6200a) should be fine but yours sounds duff.

What do you mean by "the Gas valve cover"?

A lot of these boilers/systems are a bit scaled up now so tend to overheat on "high".

 

[Doc Lenny]

Thanks for your swift Reply Chris

The plastic cover that is immediately right of the Gas Valve operating button. Seems strange I know!

The pipe that goes up to the pump is really hot on high so you may be right on it overheating. If I have the pump running on III, will that help with overheating or should I consider a new high thermostat.

Cheers

 

[Doc Lenny]

After reading another post, if my controller is not responding could this also be a faulty motorised valve?

 

[ChrisR]

Well done for reading - yes it could be a motorised valve sticking open. Sorry - don't know how many times I've suggested it before, must be age...
The clickin is just the gas solenoid opening and shutting. They don't normally make much noise though! You could turn all the power off and check the electrical connections (under the cover).

Going on/off when the boiler is up to temp, is normal.

 

[Doc Lenny]

Chris

How can I tell whether it is the vavle or the programmer? The Valve is only about 12 months old and moves freely.

 

[Doc Lenny]

The solenoid keeps clicking on off on off you get the idea, is it time to call the CORGI man?

I am pretty sick as I only wanted to save a few quid putting a couple of TRV's in. Turns out the Water pump was knackered (now replaced) programmer might be stuffed, valve may be stuffed, solenoid keep clicking - wish I was somewhere HOT!!