I had a Randall 4033 controller on my heating system and as it was a bit primitive I decided to go out and get a new controller that would allow functions like advance and different times at the weekend. I bought a “Sunvic select 207 XL” - it seemed to have the features I wanted. The instructions included how to replace a Randall 4033, and I carefully started the job. I stuck little labels on every wire as a disconnected it from the old controller, and carefully removed the controller from the wall.
Then I had a bit of trouble, I had used gaffer tape to label the wires and a very fancy roller ball pen to write on it. When I came to reconnect the wires to the new controller I found that as I had squeezed the tape onto the wires, the ink was not dry and had come off on my fingers. All my labels were now blank. Well to cut a long story short, I traced every wire in my central heating wiring so that I could find the correct wiring.
Anyway, I looked up loads of stuff about how three port valves should be wired, and mine did not seem to be like any of them. It is and old one, probably mid 70s, made by Drayton and has four wires - black white blue and yellow. This is not the same as the standard modern wiring for a valve. Additionally, the junction box in the airing cupboard has a relay, and analysis of the way this is wired would indicate that the relay is responsible for connecting the live electricity to the boiler when the boiler needs to be on. It would also appear from the wiring that the three way valve has a wire for hot water, a wire for central heating and a wire for both.
Now here is my first problem – I have searched everywhere and been unable to find any information on this valve or the wiring needed to operate it. Before I switch the thing back on I would be happier to have some information to confirm my findings.
Here is my second problem – I traced all the wires including those to the room thermostat. There are four wires on the stat: neutral on terminal 3, “CH ON” from the controller on terminal 4, and on the other two connectors, terminal 1 is connected to 4 when the room is hot, and terminal 2 is connected to 4 when the room is cold. Now there was a wire from the old controller to terminal 1, but I cannot see how is can be connected in the new wiring.
Here is my third problem – I found a black wire connected to the neutral of the pump, and I cannot find the other end of it. It is connected somewhere to the house wiring but does not come through the isolating switch that the rest of the heating wiring comes through. I found out (the hard way) that it floats up to 240V when not connected to neutral. I can think of no good reason for it to be there.
If anyone can actually bother to read all this stuff, I would appreciate some advice.
As an aside, when removing the cover to some wires in the airing cupboard, I dropped a screwdriver, and while fishing around under the hot water tank, I found that the back of my hand had become wet. The hot tank has had a slow leak for ages, and so I have also had to replace that.
And I expected this to be a simple 1/2 hour job.
Then I had a bit of trouble, I had used gaffer tape to label the wires and a very fancy roller ball pen to write on it. When I came to reconnect the wires to the new controller I found that as I had squeezed the tape onto the wires, the ink was not dry and had come off on my fingers. All my labels were now blank. Well to cut a long story short, I traced every wire in my central heating wiring so that I could find the correct wiring.
Anyway, I looked up loads of stuff about how three port valves should be wired, and mine did not seem to be like any of them. It is and old one, probably mid 70s, made by Drayton and has four wires - black white blue and yellow. This is not the same as the standard modern wiring for a valve. Additionally, the junction box in the airing cupboard has a relay, and analysis of the way this is wired would indicate that the relay is responsible for connecting the live electricity to the boiler when the boiler needs to be on. It would also appear from the wiring that the three way valve has a wire for hot water, a wire for central heating and a wire for both.
Now here is my first problem – I have searched everywhere and been unable to find any information on this valve or the wiring needed to operate it. Before I switch the thing back on I would be happier to have some information to confirm my findings.
Here is my second problem – I traced all the wires including those to the room thermostat. There are four wires on the stat: neutral on terminal 3, “CH ON” from the controller on terminal 4, and on the other two connectors, terminal 1 is connected to 4 when the room is hot, and terminal 2 is connected to 4 when the room is cold. Now there was a wire from the old controller to terminal 1, but I cannot see how is can be connected in the new wiring.
Here is my third problem – I found a black wire connected to the neutral of the pump, and I cannot find the other end of it. It is connected somewhere to the house wiring but does not come through the isolating switch that the rest of the heating wiring comes through. I found out (the hard way) that it floats up to 240V when not connected to neutral. I can think of no good reason for it to be there.
If anyone can actually bother to read all this stuff, I would appreciate some advice.
As an aside, when removing the cover to some wires in the airing cupboard, I dropped a screwdriver, and while fishing around under the hot water tank, I found that the back of my hand had become wet. The hot tank has had a slow leak for ages, and so I have also had to replace that.
And I expected this to be a simple 1/2 hour job.
