Problem with Danfoss HPA2 Valve and Heating system

[Bilko1270]

Help

I have two problems with my heating system.

1) I have a danfoss HPA2 motorised valve which is constantly closed even when the timer comes on to heat the water. If I want hot water i have to manually open it!!! Can this be fixed or do I need to replace it?

2) Now its the summer I have my system set so it doesn't come on at all however the boiler still fires up for short periods throughout the day. Any ideas why this is happening as it is very frustrating? Im burning oil but the water and heating is not on!!

Any comments on this would be appreciated.

Thanks in advance

 

[seco services]

1, sounds like the motor has failed. you can fit new motor.
check the cyl stat is sending 230 v to the valve.

2, what boiler is it ?

 

[Bilko1270]

Its a 50/70 bluebird boiler.

 

[Bilko1270]

How do I check the CYL STAT is sending 230 v to the valve?

There is power going to the connectors when the timer is set to heat the water but it stays closed.

 

[seco services]

if theirs live on the brown when the hw is calling for heat then the motors failed.

 

[Bilko1270]

Thanks for that Seco, very helpful. I will order a new motor and fit it to the current valve. (unless you think I should replace the motor and the valve)

Any ideas about my second problem?

 

[AndiiRoo]

They are a pain these things. I've just had my second one go.

The problem is they are normally closed, but if they stick half way back when the system is no longer calling for heat, power is still being sent to the boiler, which is only then regulated by the boiler thermostat itself, so it keeps switching on & off. A good reason for getting this set right beforehand i.e. only a little way above the tank stat

The CH valve went first which was easy to spot because the rads stayed red hot. The second one, recently, on the water, lead to the airing cupboard almost melting down with scalding water right down to the bottom of the tank before I cottoned on to it.

If the pump is still running with the boiler off it's a good clue. Really expensive gas waste

The manual lever on the valve stays in the Auto position so if there is a prob it might look ok, but will be 'floppy' up to mid way point, when jiggling will prob turn it off, as will also prob happen if the two retaining screws are loosened or removed. A temp fix for me was to leave the actuator top off (when it worked without the drag of the actual valve on it) & turn the valve on the pipe itself to on