Drayton LP522 controller problem

[AndyP1968]

Hi I have a boiler controlled by the above that appears to have failed. The boiler will light regardless of programmer setting; on or off etc. However it does still switch motorised valve between water and heating. The room thermostat is the only way to switch heating on or off other than mains switch. The system is 10 years old, can I easily test programmer? Thanks.

 

[sonray ltd]

If you can still control heating by stat then the stat is getting power.
check the programmer is not giving power out on heating when set to off.

 

[AndyP1968]

Thanks for the reply. I have 240 volts into the boiler in every position on the programmer, on, off etc. Unless I switch off mains. I'm thinking relay in programmer has gone.

 

[diamondgas]

Thanks for the reply. I have 240 volts into the boiler in every position on the programmer, on, off etc. Unless I switch off mains. I'm thinking relay in programmer has gone.

Do you have a 3way diverter or 'zone' valves fitted Andy? :welcome: to the forum

 

[AndyP1968]

Yes there is a 3 way valve that apears to operate normally via the programer for water.

 

[diamondgas]

Yes there is a 3 way valve that apears to operate normally via the programer for water.

Temp has gotten cold over these past few days mate! Where's your boiler situated? Do you know if you have a frost thermostat fitted?

 

[AndyP1968]

My first thought too but I can't find a frost thermostat and the boiler is in a south facing kitchen. Cheers

 

[sonray ltd]

Don't matter if you have a frost stat, you wouldn't beable to control the rads by the in door stat if frost stat had kicked in.

With programmer off, wall stat turned up so the heating kicks in check if you have 230v on the white wire to the 3 port valve.
If yes check if you have 230v to the stat from programmer.
If yes programmers faulty.

It's looking you straight in the face, if you can control it by the stat the stat is getting 230v when it shouldn't be.