Boiler Firing Constantly

[gman76]

Hoping that someone can offer some advice.

Y-plan system. During summer months, HW as normal, heating still running timed program but room stat turned right down.
On Sunday, turned room stat up (it was a bit chilly), all operated fine.
Until Tuesday, boiler stayed on constantly regardless of stats, after a few hours the house became like a sauna & the HW scolding.
Power cycled boiler on front panel - fired straight back up.
Power cycled complete system at FCU - has now been working OK.

I am concerned this may happen again & boil/collapse the CWST - not good.
Does this sound like an issue with the programmer or 3 port valve?
TIA

 

[Dan Robinson]

Mystic Meg time is it?

 

[d.j.]

Get someone out.. needs diagnostics.

 

[Stadan20]

The pilons need replacing

 

[dilalio]

Nothing wrong with the good old turn it off; wait; turn it on again

 

[dilalio]

Mystic Meg time is it?

Better than Syphilitic Sue

 

[Dan Robinson]

I am concerned this may happen again & boil/collapse the CWST - not good

Not sure why this should be a concern.

Seeing as there is no pertinent information about the boiler, I'm guessing a Wooshitter or Shiessmann.

So.... Possibly.... Trace voltage is coming off the mid position valve and firing the boiler.

Decent engineer will be able to diagnose this and remedy simply.

 

[dilalio]

Does this sound like an issue with the programmer or 3 port valve?
TIA

Well, needs testing as said but likely valve has suffered after 9 months of not moving across its full travel and microswitch sticking.

 

[dilalio]

Double post deleted.