Seeking second opinion - dodgy motorized valve?

[simonhasan]

I think the MV controlling my CH is broken - if so, how do I know which one is faulty (there are two), and should I just be replacing the Synchron motor, or the whole thing...? Any advice would be welcome, symptoms as follows...

Over the past few months my heating has taken longer and longer to come on. Of course, tonight, being one of the coldest all winter, the heating's not come on at all!

Historically, a strange electrical buzzing type of sound (think of an old Frankenstein movie), would come from the vacinity of the water tank cupboard, then eventually there would be a click and the heating would suddenly spring into life. Sometimes it would take 30-90 minutes to happen.

Hot water has always been fine. Boiler seems to work fine.
TRV's throughout the house, no central thermostat.
HW tank is a megaflow Heatrae Sadia.
Pump is a grundfos Selectric UPS 15-50 and the thing (is it the baring?) in the middle behind the aluminium screw spins when the timer's switched on. A good sign I believe?!
Two Honeywell Motorized Valves V4043H.

That's about it, thanks for any thoughts...!

 

[Agile]

You should be able to follow pipework to see which valve supplies what.

However, if you put HW on at the same time as CH then I would expect them to come on together if there is a call for HW.

If that does not happen then you may be barking up the wrong tree.

Tony

 

[pannierstan]

What you need to do is switch on heating and hot water one at a time and see which valve opens. Also which pipes get hot might help

P.S why the hell leave it till it bloody stops. If you had sorted it when it started then you wouldnt be cold now

Stan

 

[ELZ4742]

water valve will not have a brown wire where as the htg will, i would just change the whole head, its a lot less hassle IMO

 

[simonhasan]

Thanks for the thoughts and ribbing (Stan) - my girlfriend's given me a hard enough time as it is!

 

[pannierstan]

Thanks for the thoughts and ribbing (Stan) - my girlfriend's given me a hard enough time as it is!

Sorry I know but it had to be said.

Stan

 

[Agile]

water valve will not have a brown wire where as the htg will, i would just change the whole head, its a lot less hassle IMO

Surely he should expect both valves to be the same?

All of my V4043 have brown wires! Hardly a brown really more of a violet but the instructions say its brown.

Tony

 

[simonhasan]

Have just opened up the casings, and both have brown!

One of the MV's is on the Primary Flow pipe from the tank, which then connects onto the Hot Vent Pipe.

The other MV is on the connection between the Hot Flow and Hot Vent pipes

Any use?

 

[ELZ4742]

sorry guys, totally tripped out there, was thinkin that a mid pos didnt have a brown.....


anyhoo... the brown will corospond to each of the stats, ie, the heatin to the room stat and the water to the tank stat, so you can decipher which is which from that.

 

[ChrisR]

It'll be the second MV in your description.
Remove the actuator head (assuming it has a pimple on it) and see if the shaft turns its 40º or so, easily. It might be sticking/stiff.
You can see if the actuator moves correctly when off, but don't be surprised if it clunks a bit ans teeth jump. The shaft hold it lined up better!

If you open the valve to MAN then turn HW on high with boiler stat down , the rads will get warm.

 

[Slugbabydotcom]

Remove the actuator head (assuming it has a pimple on it)

Apologies for the plagiarism ChrisR but I would like to stress that this is a very important pimple that you are referring to here. NO PIMPLE = WET FEET

There's some useful info about these valves here

 

[simonhasan]

Thank you all for the advice. There's definitely a pimple on the housing...

On the MV it says that I can use a replacement Power Head 40003916, which means that I don't need to drain the system down. However, it says the wiring it is necessary to electrically isolate the WHITE conductor if the auxiliary microswitch is being used to control, for example, the system pump and boiler; if the auxiliary switch is not being used, then the GREY, ORANGE and WHITE conductors should be electrically isolated.

I don't use the auxiliary switch (assuming that's the little ever on the outside of the casing), so it looks like I'll need to isolate grey, orange, and white conductors....what does this mean!?

 

[ELZ4742]

i just means when the supply is on these will become possibly be live.

switch off the power b4 comensing work

 

[fcumswanny]

http://www.uk-plumbing.com/product2.asp?name=40003916-003

Seems a little pricey, I went to B&Q yesterday, because I've got a similar problem, and a complete new motorized valve was £36. What quality this is I don't know