Danfoss RX1 - 715si hot water issue?

[wardr77]

I hope someone can help me. Last night after a power cut the hot water seems to be permanently on. The timer unit 715si, appears to be working correctly, screen visible etc, and the central heating seems to work fine, i.e when the red light is on the rads warm up as they should and the thermostat works ok with the RX1 unit i.e I can hear the RX1 unit click on and off when I change the the temp settings. However when the red lights are off for both hot water and central heating, the boiler is still active and continues to burn on and off with what I assume to be the hot water temp, know this because the bathroom radiator is continually hot. Any ideas what the problem maybe?
Thanks in advance.

 

[picasso]

What type of motorised valves do you have ?

honeywell 2 port

• picasso
• 18 Oct 2010
• 31

0r

honeywell 3 port

• picasso
• 18 Oct 2010
• 26

 

[wardr77]

Looks like I've got two of the top one... Do you think there's a problem with them?

 

[picasso]

sounds like the hot water valve microswitch is sticking on, if the valve has a dimple on the top you can just change the actuator.

 

[wardr77]

Thanks for this. I just turned the system back on and as usual the boiler fired up (timer showing as off) I then pushed the lever on the hot water actuator from Auto to Manual, the heating 'noise' in the airing cupboard got quieter but the boiler continued to stay on...? Is this what you would expect from a faulty actuator? Thanks again

 

[picasso]

Without being there I cannot guarantee the switch is sticking but from what you have written I would think that is the problem.

 

[wardr77]

The valve is an Danfoss HPA2. Is there anyway I could check the microswitch? Or is this a pro's only check?

Thanks

 

[picasso]

If you have a multimeter and know how to use it its easy to check if the microswitch is sticking, turn off the heating and hot water at the programmer and see if you have 240vac on the orange wire, if you have one of the m/switches is stuck on, to find out which one you have to seperate the orange wires, if your not comfortable working with mains voltage I recommend you get someone that is to check the wiring out for you.

 

[wardr77]

Just to say thanks for all your advice, much appreciated.

 

[picasso]

Your welcome, hope you get it sorted.