New board in suprima made things worse!

[spike66k]

Put a new board and thermistor in my suprima 50 as the boiler repeatedly blew out. 4 days of everything working fine for a change, then tonight it started blowing out again and wont even let me restart the boiler at the restart switch. Coincidentally, when i turn OFF the room thermostat.... the boiler and pump start to work!!!!!!!
Any suggestions please?

Spike

 

[ollski]

sounds more like your motorized valve.....is the programmer and cylinder stat calling for heat when you are turning down you room stat?. Try turning the cylinder stat down completely and see if it fires up then. If not look at a new synchron motor in your valve or possibly a head unit.