Honeywell V4073A - Orange wire staying live?

[franktank]

Hi everyone,

Real quick one (Hopefully) I'm in the middle of renovating a house, and I'm trying to sort the central heating.

It's a Worcester Bosch 24ri, and I've noticed when I'm working round the house, the boiler is constantly cutting in all the time. The pump seems to be running all the time also. Anyway I started a little investigative work today after reading up on the valves and realised the orange wire turns the boiler on (I know it's also linked into the HW demand also)

I turned the programmer to off (both HW and CH) and there appears to be a residual voltage of about 50 to 80VAC on the orange wire. This voltage is obviously enough to keep the relay/input to the boiler pulled in and the boiler firing all the time. If I cut the power to everything, then power back up, this voltage sits at 0v (the spring has pulled the valve back when I do this)

So, I assume this residual voltage on the orange wire is keeping the boiler going. Is this normal for the V4073A or are the electronics on the head knackered? Should I replace it with something other than a Honeywell? (A search seemed to reveal a Siemens valve doesn't suffer with this voltage issue?)

Thanks alll

Ben

 

[Boilerman2]

If you feel confident, take out the orange wire from it's terminal in the junction box, a see if the voltage is actually being generated by the actuator or if it it is present in the system (check the terminal that the orange came out of) it is possible that the microswitch in the actuator is faulty, however the hot water cylinder stat also puts a feed onto the same terminal as the orange, hence my suggestion of separating the orange from the rest of the wiring

P.S. Seimens valves are carp!! stick with honeywell

 

[picasso]

Its a fairly well known problem with the honeywell valve, a resistor between the orange and neutral will sort it out, if you do a search on this site there are posts with exactly what resistor value you need.

 

[franktank]

Hi Boilerman,

Thank you, I must apologise for forgetting to mention in my first post, I'd pulled the orange wire out from the terminal block and it was indeed staying alive (The orange lead) So I think you've confirmed my suspicions about it being the actuator.

Only question now is, do I replace:

1) The microswitch
2) The head
3) the complete thing?

Reason I ask, I think the system is full of crap currently (I dread to think the state of the heat exchanger in the boiler) confirmed when I replaced the pump last weekend, and the impeller seemed to be full of radiator debris

The whole system had been sitting unused for at least 18 months, and both fan and gas valve have been replaced in the boiler as they were knackered. Which I think, is all tied into the boiler running permanently for a while!

 

[Agincourt1415]

is this a mid position valve if so im sure u get the 80v from the mini pcb in the 3 port valve. and in any case 80v should not power a boiler. [/youtube]

 

[franktank]

Thanks again gents.

I'll investigate the use of a resistor, as I think (from searching on here, some Worcester Bosch boilers will fire up with a comparatively low voltage on the orange wire)

Incidentally, I'm sure from me messing about earlier, when I switched to CH only, the valve appeared to get stuck in the CH position, and wouldn't move back to HW only, unless I killed the power and let the spring return it...

Thanks all

Ben

 

[swbjackson]

Honeywell valves will stay in the heating position until there is a call for hot water or the power is turned off.

 

[snb]

there is a known problem with these worcester boiler pcbs. They have modified the board to overcome this. Or the other alternative is to replace with two 2 ports

 

[vicvapour]

Its a fairly well known problem with the honeywell valve, a resistor between the orange and neutral will sort it out, if you do a search on this site there are posts with exactly what resistor value you need.

There's actually two resistors in the mid-position valve

The first resistor (13k 2W) produces DC current with the diode , so the motor can stall in any position.

The second resistor (13k 2W) generates a small AC surrent to demagnetize the motor from the effect of the rectified Direct Current that is used to hold it in the mid-position.

 

[picasso]

I think your missing the point vic, the resistor between the orange and neutral kills the voltage from the 3 port valve that is causing the boiler to run.

 

[vicvapour]

I think your missing the point vic, the resistor between the orange and neutral kills the voltage from the 3 port valve that is causing the boiler to run.

Not sure whether the resistor kills the voltage my friend. I understood the orange wire need to be energised in order to fire the pump and boiler.

 

[picasso]

Honeywell 3 port valves can have about 80vac on the orange wires depending on the last position of the valve,

worcester boilers seem to be affected by this voltage(causing the boiler to fire) and the solution was to fit a resistor between the orange and the neutral, it does not stop the boiler from running when 230vac is applied to the orange.

 

[vicvapour]

Honeywell 3 port valves can have about 80vac on the orange wires depending on the last position of the valve,

worcester boilers seem to be affected by this voltage(causing the boiler to fire) and the solution was to fit a resistor between the orange and the neutral, it does not stop the boiler from running when 230vac is applied to the orange.

Ah yes , i remember hearing about this, at least the problem is sorted out now, so in the older models the solution for troublesome ports is a direct swap to the newer model probably.

 

[franktank]

Thanks for all the help Gents.

After a lot of searching on here, it seems the Worcester Bosch fix for earlier boilers is to fit a 0.47uF 250V capacitor between the orange and neutral. The cap leaks enough of the voltage away to stop the boiler firing by all accounts and it's fixed my problem!

This probably goes to explain why my boilers fan had failed seeing as the bolier had been running constantly for the last few years (Before I'd purchased the property)

Anyway, I now have another issue which is another topic...

 

[foxhole]

Sorry to hijack but I have same problem with a new Worcester greenstar boiler, but with a Horstmann 3 Port valve. Heating comes on with heating set to off , but if I turn on Hot water for an hour it stops the boiler [unless stat on tank asks for hot water of course].I thought it might be the valve not returning after the heating is turned off but if like the Honeywell it's still producing a small voltage would the resistor work for me? My heating engineer suggested changing to Honeywell valve but would seem from everyone's postings that it is unlikely to help.