Heating or heating and water randomly staying on

[woldsweather]

Our gas central heating comes on for an hour and a half in the morning at lunchtime it is set for on 1200 off 1200 and in the evening 1700-2200. Since we moved into the house 2 years ago it has randomly just failed to go off. For example the heating was on 1 pm ish twice last week. It can go 10 days without doing it. The first gas safe engineer I had changed the timer controller. That didn't fix it. The second replaced 2 valves, still no joy. So neither has any idea what this could be.

Any ideas?

 

[heatservice]

What make & model have you got, have you spoken to the manufacturers, with so much being controlled by microchips these days it could be one of several things.

 

[king of pipes]

Do you have a 3 port valve ?

 

[SimonG]

It's getting a live from somewhere.

Find somebody who will get the testers out before throwing parts at it.

 

[woldsweather]

The boiler is a Worcester. Going to get the wiring checked. Presumably whoever installed the new controller wired it like for like and so the problem followed through to the new one?

 

[heatservice]

Really cant see the programmer could be at fualt especially as its been changed but didn't cure the intermittent fault, more likly to be the boilers frost protection or anti -seize function causing it.

 

[woldsweather]

Would that cause the timer controls orange light(s) to come on?

 

[jtsplumbing]

Would that cause the timer controls orange light(s) to come on?

That sounds more like a faulty controller ! phone the makers and speak to there Tec dept.

 

[woldsweather]

The identical fault to the controller it replaced?

 

[SimonG]

Should never assume it's 100% out of the box.

 

[heatservice]

The only programmer I can remember where the orange lights would come on when there was no demand was an old Landis & Gyr RWB2 mechanical type but the boiler didn't fire up it was feedback from the 3 port valve I think. Have you asked Worcester if thay have had others with the same problem?

 

[S.P.S.]

Did your last guys actually check anything with a multimeter? I’ve had zone valves send live up orange off their own accord!