Anyone knows where I can get a Randal 3033 Timer Controller.

[Benny5]

My existing Randall 3033 Timer Controller unit appear to be in a state of decline. It’s become very noisy but more important is the fact the boiler has started to fire up when the power to the controller is switched on.
My system comprises;
Baxi Solo 2 RS50.
Randal 3033 Timer Controller.
2 x Honeywell V4043 motorised valves; managing hot water and central heating.

I have looked into the possibility of a faulty valve; however, when I switch the H/W to ON/OFF I can detect movements as the valve opens and close. The same applies to the C/H.

Any assistance appreciated.

 

[D_Hailsham]

My existing Randall 3033 Timer Controller unit appear to be in a state of decline. It’s become very noisy but more important is the fact the boiler has started to fire up when the power to the controller is switched on.

Do you mean with the HW and CH both set to OFF?

I have looked into the possibility of a faulty valve; however, when I switch the H/W to ON/OFF I can detect movements as the valve opens and close. The same applies to the C/H.

The valves may be opening and closing, but the microswitches within the valves may be sticking open or closed.

Do you have (and know how to use) a multimeter?

 

[Benny5]

Thank you for your prompt response.

Do you mean with the HW and CH both set to OFF? -- Yes. Both OFF.


Do you have (and know how to use) a multimeter? ---I have got a rather old one not exactly proficient in its use though.

 

[D_Hailsham]

Do you mean with the HW and CH both set to OFF? -- Yes. Both OFF.

Presumably when you switch on the power to the controller that also switches on the power to everything else. If so, you could have a motorized valve with the microswitch contacts stuck together.

Do you have (and know how to use) a multimeter? ---I have got a rather old one not exactly proficient in its use though.

As long as it can measure AC volts, it will do. Set it to the range which can exceed 240Vac.

I will assume that all the components are connected into a wiring centre (junction box).

Turn the power off
Set programmer to CH and HW OFF
Turn CH and HW stats to MIN
Remove junction box lid
Identify the terminal where the valve wires are connected
Disconnect both Oranges (they go to the same terminal - make a note!)

Turn power ON
Warning: The Orange wires may be LIVE
Measure voltage between Brown and Blue for both valves - should be 240Vac
Measure Grey to Blue - should be 240Vac for both valves
Measure Orange to Blue - should be 0Vac for both valves.

If it is 240Vac, the microswitch contacts on that valve are stuck together.

Do these tests and come back with the results. Then you will get the next appropriate tests.

 

[Benny5]

Once again many thanks for your help.

Well the terminal box is like a birds nest. This is what I have established I hope it make sense;

Warning: The Orange wires may be LIVE - Yes they were live.
Measure voltage between Brown and Blue for both valves - should be 240Vac. 0Vac registering!!!
Measure Grey to Blue - should be 240Vac for both valves. Both 240Vac.
Measure Orange to Blue - should be 0Vac for both valves. H/W = 0Vac. C/H = 240V ac.


So apart from a noisy switch do I have a faulty valve??

 

[gasafengineer]

Warning: The Orange wires may be LIVE - Yes they were live.
Measure voltage between Brown and Blue for both valves - should be 240Vac. 0Vac registering!!!
Measure Grey to Blue - should be 240Vac for both valves. Both 240Vac.
Measure Orange to Blue - should be 0Vac for both valves. H/W = 0Vac. C/H = 240V ac.

Maybe an oversight on D-Hailshams advise to you but going with the advise he gave...........................

grey/blue should show 240 volt
brown/blue should show 0 volt
orange/blue should show 0 volt

if grey & orange both show 240 volt with programmer/stats OFF i would suspect faulty micro switch.

 

[D_Hailsham]

Warning: The Orange wires may be LIVE - Yes they were live.
Measure voltage between Brown and Blue for both valves - should be 240Vac. 0Vac registering!!!
Measure Grey to Blue - should be 240Vac for both valves. Both 240Vac.
Measure Orange to Blue - should be 0Vac for both valves. H/W = 0Vac. C/H = 240V ac.

Maybe an oversight on D-Hailshams advise to you but going with the advise he gave...........................

grey/blue should show 240 volt
brown/blue should show 0 volt
orange/blue should show 0 volt

if grey & orange both show 240 volt with programmer/stats OFF i would suspect faulty micro switch.

Thanks for picking that up. I had forgotten that I asked for the stat to be turned to MIN.

Brown - Blue will become 240Vac when the stat is turned to max.
Orange - Blue should then go to 240Vac

240Vac on the Orange with the stat turned down suggest a sticking microswitch.

 

[gasafengineer]

 

[Benny5]

So hopefully I can get a replacement power head for the C/H valve, thus avoiding a system drain down.
I will probably replace the Timer Controller at the same time as the noise is becoming too much. From what I have seen the Danfoss Randall 4033 looks pretty similar (same back plate), with installation involving just minor wiring changes.

Once again I would like to extend a big thank you to gasafengineer and D_Hailsham for your invaluable assistance with this problem.

Best regards,
Benny.

 

[D_Hailsham]

So hopefully I can get a replacement power head for the C/H valve, thus avoiding a system drain down.

Does your actuator cover have a small bump on the top at one end?

If it does, your in luck as the actuator can be changed without draining down. But if there is no bump, you will have to change the complete valve, which means draining down.

I will probably replace the Timer Controller at the same time as the noise is becoming too much. From what I have seen the Danfoss Randall 4033 looks pretty similar (same back plate), with installation involving just minor wiring changes.

It might be a suitable time to consider something more up-to-date than a 24 hr mechanical timer with common heating and hot water times. And if you have an old mechanical thermostat a change to a digital one would be a good idea as they are more accurate and maintain a more constant temperature.

 

[Benny5]

Does your actuator cover have a small bump on the top at one end?

They are both V4043H, the faulty one is the newer of the two and it has, what could be best described as, a dimple on the top edge of the cover. Its construction is different to the older one in that it appears to have three fixing point to the valve. While the old one simply sits on a plate. I don’t know if you can make any judgement based on that limited information.

 

[D_Hailsham]

They are both V4043H, the faulty one is the newer of the two and it has, what could be best described as, a dimple on the top edge of the cover.

That sound like the version with the removable actuator (the design changed in 1987!).

 

[Benny5]

I have had a fresh look at this today.
One of the valves (the suspect one) is tucked away in the airing cupboard and not easily accessible. However, while it appears identical to the Honeywell V4073 on closer examination I now discover it is in fact a Landis & Staefa; Part code ZAV-222, BG Code 397749. All of which suggests a complete replacement.
Before I go down this route I am just looking for confirmation that a replacement will clear the fault. I have now disconnected unit from the system and find the ’stand alone’ H/W system functions normally.

I am just wondering if there is any test I can now carry out on the disconnected unit to confirm the faulty micro switch. Is there any continuity testing that can be carried out.

Regards,

Benny.

 

[Benny5]

.

I am just wondering if there is any test I can now carry out on the disconnected unit to confirm the faulty micro switch. Is there any continuity testing that can be carried out.

Regards,

Benny.

Just an update; I have put the meter across the various leads and these were the results;

Brown - Blue. picking up resistance.
Orange - Grey. picking up resistance.

Nothing for any other combinations.

 

[D_Hailsham]

I have put the meter across the various leads and these were the results;

Brown - Blue. picking up resistance.
Orange - Grey. picking up resistance.

Nothing for any other combinations.

I didn't ask you to test the resistances but the voltages


Do the tests I suggested.