Replaced Actuator not working properly
- Thread starter dmilbank
- Start date
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The indicator should be showing M (mid position) and the boiler should light.
The white wire may not be connected correctly. (This is where you can use your neon screwdriver.)
Disconnect the white and grey valve wires.
Turn CH ON
Using screwdriver find which of the two terminals (cream and yellow) goes live when the room stat is turned up.
You connect the white wire to this terminal.
Leave the grey disconnected and check the boiler lights and you get HW and CH
Did you check that the cream terminal went live when stat turned up and dead when stat turned down?
Can you check the yellow terminal? It should be 240V when the HW stat is turned down or HW is OFF and 0V when HW is ON and HW stat turned up.
That's OK
That's wrong. The valve should go to mid-position and boiler light. When the valve is in mid-position, the boiler is lit via the HW thermostat, which we know is OK.
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Curiouser and curiouser!
Does the Yellow terminal respond to the CH stat turned up and down when CH is ON? If so, that is the correct terminal for the valve White wire.
Now check the white terminal. Does it have 240V when the HW stat is turned down or HW is OFF and 0V when HW is ON and HW stat turned up? If so that is the correct terminal for the grey wire.
Should I have turned off power to reset actuator before doing your latest test? Actuator is still over to CH!
No voltage when HW on stat is down/off or when switched on & up.
Now check the white terminal. Does it have 240V when the HW stat is turned down or HW is OFF and 0V when HW is ON and HW stat turned up? If so that is the correct terminal for the grey wire.
No voltage when HW on stat is down/off or when switched on & up.
No. What I should have said was disconnect the white wire first.
Presumably CH was ON?
That's not quite what I asked for. You should get the following:
Programmer HW ON + HW Stat Up = 0V
Programmer HW ON + HW Stat Down = 240V
Programmer HW OFF + HW Stat Down = 240V
Programmer HW OFF + HW Stat Up = 240V
What make and model is your programmer?
Can you post a pic of the junction box, so we can see the wiring?
CH was switched on when I checked yellow
To confirm, there was no power to the white terminal during any of the 4 combinations.
My programmer is a Potterton EP 2002
The actuator is wired to a connecting block ( as in my diagram) which in turn goes to a junction box. Which do you need to see?
To confirm, there was no power to the white terminal during any of the 4 combinations.
My programmer is a Potterton EP 2002
The actuator is wired to a connecting block ( as in my diagram) which in turn goes to a junction box. Which do you need to see?
We need to positively identify what the cream and yellow terminals do.
Reset the valve and disconnect valve white and grey.
With Programmer CH ON, test both cream and yellow to see which one is dead when CH stat is down and live when CH stat is up. This one is the white wire terminal.
Also repeat the four HW tests on both cream and yellow. You should get the correct results on the opposite one to CH tests.
If you do not get the expected results, there is either a wiring error or the programmer is faulty.
Is the junction box part of the programmer or separate from it? If part, I only need a pic of the junction box. But is separate, I need a pic of both junction box and terminals within the programmer.
There is a junction box in the hot water cupboard, that goes to the connecting block then to the actuator. The controller is situated down stairs. I will photograph all and post. I really do appreciate your time taken so far.
I have to go out now & it is going to be dark soon, so will start again in the morning.
I have to go out now & it is going to be dark soon, so will start again in the morning.
I have taken up a lot of time trying to sort this problem with great advise from members. Still unable to sort and in desperation, I called in a local heating engineer. He came recommended and seemed very professional but has now spent six hours trying to figure out the wiring of my system! He now seems unable to explain why a terminal remains live on the connecting block despite everything being switch off. He has narrowed down to a potentially faulty frost stat.
I am not convinced that he is fully capable of solving this problem. He is a capable plumber, but doesn't convince me he is fully qualified in electrics. After six hours I am no nearer to getting my actuator to work properly! He is due to return to fit a new frost stat to either solve or eliminate this from his investigation.
I need to ask if this sort of problem warrants in excess of six hours just to find a fault, if any, in a wiring system that has performed without problem for the six years we have lived in this house. Up until trying to replace the actuator, all has been working fine.
Should I continue with present engineer, even if its only for another hour to test the frost stat, or should I cut my losses and try to find an electrical expert?
If second option, how do I find a reliable one?
I am not convinced that he is fully capable of solving this problem. He is a capable plumber, but doesn't convince me he is fully qualified in electrics. After six hours I am no nearer to getting my actuator to work properly! He is due to return to fit a new frost stat to either solve or eliminate this from his investigation.
I need to ask if this sort of problem warrants in excess of six hours just to find a fault, if any, in a wiring system that has performed without problem for the six years we have lived in this house. Up until trying to replace the actuator, all has been working fine.
Should I continue with present engineer, even if its only for another hour to test the frost stat, or should I cut my losses and try to find an electrical expert?
If second option, how do I find a reliable one?
That is excessive. Hidden wires make life difficult, but you should be able to produce a circuit diagram in under an hour.
Yes,that is the real problem.
I hadn't thought of a frost stat.
If the stat is external to the boiler, there is no need to replace it to check if it is faulty. All you have to do is disconnect it and see if the problem goes away!!
That's cobblers.
A frost stat is always in parallel with the programmer and room stat so, when the heating is turned off, it will bring the boiler on if the temperature drops too low.
In any case an external frost stat can be adjusted. All the "engineer" needed to do was turn the stat down and see if the problem went away.
The standard way of wiring a frost stat with a mid-position valve is to connect it to the valve white wire. This ensures that there is circulation through the radiators when the frost stat lights the boiler.
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