Rads on even with CH turned off

[KennyPowers]

Hi,

My radiators are still heating up, even though CH is off, and just HW is on.

Looking online it seems this may be down to a duff actuator or valve on the 3 way junction bit.

I have a BGMVSP-23 Mid Position Actuator, which has a little black lever on the side. This does not want to budge, so assuming this is a manual override lever, would this mean the valve is seized?

I could change an actuator head myself if needs be, but I think changing the whole valve might be a bit beyond me (would involve draining the whole system?)

Any help greatly appreciated.

 

[D_Hailsham]

There are two levers! The lever in the slot labelled W M H is just an indicator to show which position the valve is in (hot Water, Mid position, Heating). There is also a lever at the end, which can be used to open the valve when refilling the system. You have to pull the lever out before it can be moved in the slot.

Turn off the power to the system; this resets the valve to HW only position. You should feel resistance when the end lever is moved along the slot; it should automatically return to the starting position when released. If there is no resistance the valve is stuck open.

Feeling the pipe from valve to rads will also tell you if it is stuck open in mid or CH position.

 

[KennyPowers]

Update: did what you said, moved the lever which felt a little bit of resistance, then let go and it attempted to return to closed position, but didn't seem to have enough 'oompf' to fully close again.

Something was rattling inside as well, so I opened the box up, and a bit of plastic plus a spring fell out. So I'm assuming that because it only has one working spring left, that is why it won't close the rads off properly.

I've found a replacement on Screwfix (£70!), which is the same model re-badged basically. Question is, could I get a different model (like a more reliable make) and still use the existing valve pipework, or are the valves and actuators unique to each other?

Thanks.

 

[Ihavenojob]

Just change the head (actuator) as these are one of the more reliable valves . They are rebranded drayton valves. I have repaired loads of these by using a small nut & bolt to replace the broken lug. You can get the head a lot cheaper on eBay .

 

[KennyPowers]

Did what you said, ordered a Drayton MA1 off ebay for £45, so cheaper than Screwfix.

Last night I took the actuator off, and manually closed the valve with a spanner in the position shown below.

However this morning when the heating came on, the rads were still getting warm. So perhaps the valve is letting the water through still?

I will check again when I get home that it is not just old hot water still in the system cycling around the rads, but the rads on the landing were quite hot!

 

[Ihavenojob]

If you carefully take the circlip off the spindle, you can then turn it each way till it stops then push it in & out a few times, this MAY remove some debris from the paddle/port faces. You can also lubricate the spindle with oil at the same time, refit clip .

 

[D_Hailsham]

You can also lubricate the spindle with oil at the same time.

Oil, and WD40, are the last thing to use; they will rot the seals. Use a silicon-based lubricant.

 

[Ihavenojob]

No, use oil.

 

[D_Hailsham]

No, use oil.

We'll have to agree to differ.

 

[KennyPowers]

Ok thanks.

I think which lube to use is the least of my problems right now!

Just got home from work in time for the hot water to come on - the upstairs rads are still getting hot, the downstairs ones warm. This is with the actuator head off, and I've manually turned the valve CH off with pliers.

I have an idea that maybe the valve is letting a bit of water through to the rads, as there needs a bit of pressure on the valve constantly to keep it 100% shut? I.e. the spring pressure from the actuator head is needed to fully close the valve, whereas I have the defective actuator head off, so the valve is only 95% shut?

I will attach the new Drayton actuator head tomorrow, so hopefully all will be correct then. Really don't want to have to change/mess around with the wet side too much.

 

[D_Hailsham]

Have you lived in the house for some time and this is the first time the fault has occurred?

 

[KennyPowers]

Only been in house just over 3 years, never had his particular problem before.

The other week I put the rads on as the weather had starting getting cooler (just to test them). So for months it must have been stuck in the HW open, CH closed position over summer.

 

[AGAS]

just see if you can turn the spindle with your fingers easily , if you can just crack on and change the head

 

[KennyPowers]

Spindle is turnable by fingers. One thing I notice was when the spindle was in the 12 o'clock position (for hot water only), it would not go exactly to 12, just slightly off. You can see this in the picture below as the indicator lever is not fully across.

Could this be an issue? I did take the little horseshoe surclip off the spindle, and push it in/out gently to see if it dislodged anything.

Replacement Drayton fitted: