Boiler lock out, thermostat faulty?

[lora]

Posted earlier this week about a wireless thermostat.

Situation is this; Halsteads Platinum, booked a fixed price repair (knew there were a few things needing doing) so far; 2 PCBs, 1 water gauge and a water leak fixed it still goes to lock out at random. First PCB it worked for 2 hours, went off, couldn't get it back on, 2nd PCB fitted - didn't work straight away, he found some 'jammed pin' and sorted that out. Left it in the diagnostic mode, I switched it over to timer the next day, it went off an hour later.
Phoned them up again. This guy has it down as the thermostat, or wiring to, fair enough. Seemed to get it working, it went off the morning after. After messing with the dials through the weekend I managed to get it to fire up with the heating on 'constant' and the room thermostat turned up to maximum.. It would come on at random for a minute every 10 minutes and would go off whenever I switched it to the timer, I felt this could well be the thermostat. It's gone off tonight and cannot get it to fire up at all - tried switching the central heating to standby and turning the timer off but everytime I try to reset it just goes to lockout, can't get it to start at all - so no hot water. Surely if there's no demand for heat it doesn't matter if the thermostat is working or am I being thick?

Not yet replaced the thermostat, was after having a wireless one but given the one price I've managed to get to 'supply and fit' and the various 'I don't touch gas', 'you need an electrician' and none-ring-backs I'm beginning to despair...not even sure that'd solve the problem.

 

[ChrisR]

If you mean the room thermostat you're right, it isn't the problem. SO we have to wonder about your man .

DOn't run the beast in Service mode.

Do you have the service/installation instructions? See H site.

WIth no call for CH or HW, turn mains off for a few seconds then back on.
Boiler tests itself. If it goes to lockout, press and hold Reset for 3 seconds, and the 4 leds on the front show an error code indicating the fault. If that doesn't work, pcb - again?

 

[lora]

It was the repair chap that'd left it in diagnostic mode - when I called back they tried saying I'd have to pay this time since it would be a different problem, I argued that it hadn't been left fully-functioning..

Bizarrely enough after 2 hours of trying to reset with no success I turned the thermostat to minimum in desperation - tried the reset and it worked....the thermostat is old, at least 20 years, a cheap replacement might be in order (the wireless programmable was just a pipe dream). And if no better at least I can argue that away next time I ring up.

 

[bengasman]

Boiler should not have been left in diagnostic mode. Your paid to get a working boiler without having to fiddle yourself.
Get them back and do not change anything yourself or they can argue your diy has invalidated the warrantee.