2 zone valve question

PoGee

We've had problems with heating - hot water ok but radiators cold. Fault is with zone valve. If I move it to manual, get hot water and heating but don't think the thermostat or timer will work. I can control it if I move the timer to 'on' for both heat and water but it just says on.
Question - if I use specialist wd-40 on the zone valve, is that safe? If I leave on manual and switch boiler on a few hrs a day, will the boiler or zone valve overheat?
The boiler has a separate valve at the top that releases steam once switched off (has always done this, even when working ok)

WIAWSNB

Hi PoGee.

I'm alarmed at your steam release - could you provide more details, please, and ideally a photo?

Is this a really old boiler?! Vented or sealed system - does it have a pressure gauge? 

And could you clarify, please - is that a two-port valve, or three? Ie, how many pipe connections does it have? From that stock pic I'm guessing the former, in which case do you have two of them?

PoGee

Thanks for your help WIAWSNB. When I asked about the steam release a few years back, British Gas said it was a good thing as new boilers don't have that pressure valve + end up overheating. I'm not sure if there are 2 of them - it's under the floorboards and I've just moved everything back. I'll take another look at the weekend. The boiler is about 32 years old.

Rodders53

The motor driving the valve open (it closes on a spring) has likely failed. 
New valve head required.

WD40 will do nothing useful.

{Other fault could be the timer for CH or room thermostat not switching mains to the motorised valve.}

PoGee

Rodders53 said:

The motor driving the valve open (it closes on a spring) has likely failed. 
New valve head required.

WD40 will do nothing useful.

{Other fault could be the timer for CH or room thermostat not switching mains to the motorised valve.}

The first issue noted was that it would take ages for the radiators to heat up and then stopped heating up altogether. I thought it might be the valve being a bit sticky and taking forever to move back and forth. I really need a new heating system but can't face the upheaval at the moment. It's something I'd like to get done in 12 - 18 months, when I retire. That's why I wondered if WD 40 could be a temporary fix or is wd40 near the valve a complete no-no?

WIAWSNB

PoGee said:

Thanks for your help WIAWSNB. When I asked about the steam release a few years back, British Gas said it was a good thing as new boilers don't have that pressure valve + end up overheating. I'm not sure if there are 2 of them - it's under the floorboards and I've just moved everything back. I'll take another look at the weekend. The boiler is about 32 years old.

Thanks.

That, I believe, is an air vent valve. It is used to release any air in the system, which could cause issues. Nice thing to have, especially at high pipe spots (I have one), but it shouldn't 'vent' on a regular basis - that would indicate that air is being drawn in to your system - not good - or 'gas' (possibly hydrogen) is being created in your system due to corrosion - even worse.

Anyhoo, you haven't described the type of motorised valves you have, or how many. 

And, are you capable of wiring a plug without killing yourself?

PoGee

The motorised valve we have is like the one in the 2nd pic. The timer is the same as pic 1. I'm not sure how many we have because I put the floorboards back on and moved furniture over them. I can wire a plug - is it the same kind of idea? Will probably just buy the part and get an engineer in.

WIAWSNB

PoGee said:

The motorised valve we have is like the one in the 2nd pic. The timer is the same as pic 1. I'm not sure how many we have because I put the floorboards back on and moved furniture over them. I can wire a plug - is it the same kind of idea? Will probably just buy the part and get an engineer in.

These are under the floor?! Lawdie.
Ok, if it's a faulty motorised valve, and they do tend to fail after 10-odd years, then there's two fixes. One is to replace the whole valve, which means draining your CH system, and the other is replace just the 'head', which is DIYable with basic wiring skills.
Especially for the former, then assuming there are two, replace them both. 

PoGee

Thanks again WIAWSNB. Yes the motorised valve is under the floorboards. Probably will be another one somewhere. What's the downside if I keep it at the manual setting and only turn on a few hours a day? Is it dangerous?

Section62

PoGee said:

Thanks again WIAWSNB. Yes the motorised valve is under the floorboards. Probably will be another one somewhere. What's the downside if I keep it at the manual setting and only turn on a few hours a day? Is it dangerous?

Depending on the make/model the manual setting is only meant to be used when the valve is de-energised (all power to the heating system switched off).  The purpose of the setting is to allow the system to be fully drained.

Some manufacturers give warnings that using the manual setting whilst the valve is energised may cause damage to the valve.

Some types can get quite hot when operating.  Typically the motor runs until it stalls (due to the force of the return spring) after which the power continues to flow through the motor to keep it in the stalled position.  It isn't a great idea to have one installed under floorboards - from the maintenance point of view, and also in case it is overheating/failing - so might be worth having a conversation with a plumber about options for relocating it.