Intermittent hot water problem

[jaretti]

Hi all,
Just like from title for the last 2 nights our water didn't get heated.

So today I manually on a programmer switched water - nothing. Programmer light went on, but boiler and pump didn't kick in.
Tried same thing 10 minutes later - everything worked. So obviously something isn't switching on when it's supposed to.

So now I want to find out what causing the problem.
Programmer seems operate normally. 3port valve shouldn't be a problem, as it's summer and we not using heating so it stays in same position...UNLESS signal goes through it. Which leaves pump and boiler...

We have conventional system with honeywell programmer, grundfoss alpha2 pump, Baxi boiler and danfoss(I think) 3 port valve.

Any ideas anyone???

 

[picasso]

Cylinder stat perhaps but you really need a multimeter to follow the signal from the programmer to the boiler.

 

[jaretti]

Hi,
Thanks for advice Picasso, got new stat, changed, worked for 2 days, then same thing.
Googled my programmer st9400c, turns out that when led is on it doesn't send enough voltage to boiler. Switched off led, working now, hopefully will stay like that.
Tomorrow will write email to Honeywell customer services, hopefully they can send me a replacement.