3 way diverter valve actuator

Belenus

Hello

Potterton Powermax HE 150 boiler.

The CH radiators are getting hot on Hot Water only which suggests a sticking 3 way valve or a sticking actuator. It is probably stuck half way as the water also gets hot. I don't know if it the actuator or the valve itself that is sticking.

The actuator is a Honeywell VC4012-34  (Baxi/Potterton reference is 5107000)

Here is a picture of a similar actuator. It attaches to the 3 way valve.



That little white piece jutting out from the slot indicates whether the actuator is set for HW or CH. It moves from top to bottom accordingly.

Does that white indicator also act as a manual control to move the valve or is it an indicator only and isn't robust enough to move the valve? In previous houses the 3 way valve had a metal manual control.

If the actuator is removed, is it possible to manually rotate the valve, which might clear anything that might be causing it to stick.

It it is the actuator that has failed I can buy a replacement, about £80 new or £20 to £30 second hand. I could fit it myself buy I will probably get a local gas safe person to do that.

If it is the valve itself I will call in Baxi/Potterton as I don't want to have to drain down the system etc.

Comments, advice or suggestions are welcome.

Thanks

fenwick458

just get a plumber to fit you a new 3 way valve, it's worth getting them to supply and fit

Jeepers_Creepers

To try and answer your Qs, Belenus, most likely that lever is strong enough to move the valve and motor, as that is one of it's purposes - used, for example, to keep the valve manually open during system fills. But don't come crying to me if it snaps...

(You are going to replace the head anyway   )

Yes, if you remove the head, you should be able to check the actual valve operation. It should be smooth to move through an 'arc' - I dunno, around 30o or so? - and make a firm 'thunk' at each end as the valve seats against each opening. If it seems ok, it likely will be ok, so just replace the head for now if you can DIY this. Oh, of course there should be no signs of leakage around the spindle.

If it makes financial sense to buy the whole valve, simply keep the valve body safe nearby until you need to drain the system for a different reason, and then ask the plumber to swap that bit too.

Are you up for a DIY head-swap?

Belenus

Thanks J_C.

Yes, I am happy to do a head swap. I have done it before and it is very straightforward. I won't tackle a valve swap. I'd prefer to get a professional in for that. The boiler is on the first floor so a big leak or flood could do a lot of damage.

I will open up the boiler tomorrow and investigate. I have seen a second hand actuator for sale for £20 which is probably worth a punt.

The alternative is probably several hundred pounds with a local gas safe person or about £350 for Baxi/Potterton. The latter does include a one year insurance deal via D&G. The boiler is now 16 years old so I may consider that if the £20 valve doesn't work.

Thanks again.

Jeepers_Creepers

Hang on! That little baby has a plug-in cable! Have you ever fallen off a log? Well this is easier...

Your call, but what I would do is first remove the old head (I bet that's a 2 minute job), and check the condition and operation of the valve below (as I outlined before). If you are confident that the valve itself is fine, then just buy a NEW head for £40 - daft going 2nd hand, I think.

I'm sure there's plenty other places: https://www.ebay.co.uk/itm/331430813905?chn=ps&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&itemid=331430813905&targetid=1141640586891&device=c&mktype=pla&googleloc=9045292&poi=&campaignid=12125450855&mkgroupid=118098821258&rlsatarget=pla-1141640586891&abcId=9300480&merchantid=101735791&gclid=EAIaIQobChMIk9CM0eqM7wIVYoBQBh3baQCAEAQYASABEgIfMPD_BwE

Belenus

Jeepers_Creepers said:

Hang on! That little baby has a plug-in cable! Have you ever fallen off a log? Well this is easier...

Your call, but what I would do is first remove the old head (I bet that's a 2 minute job), and check the condition and operation of the valve below (as I outlined before). If you are confident that the valve itself is fine, then just buy a NEW head for £40 - daft going 2nd hand, I think.

Thanks JC. I got round to removing the actuator today. It was a 30 minute job as I had to remove all the cover panels and also some internal panels to access it. It is buried deep inside behind the control panel. See picture of my  boiler below.

I can't tell if it is the actuator or the valve itself that is sticking. I watched some YouTube videos where the valve has a spindle that moves through about 20 degrees. My valve appears to have a sprung push mechanism that moves forward and backwards.

Here is a photo of the actuator. As you can see it says to use an identical actuator. I have found a new one on eBay for £42.90 so I have taken a  chance and bought that.  Hopefully it fixes the problem. If not I will get a professional to swap the valve itself. I really don't fancy tackling that myself. I could do it if it was open plumbing in an airing cupboard but everything is crammed tight inside this integrated boiler.

I have put the actuator back on and refitted all the panels and the fault is still there. At least both the HW and CH are working. The radiators heat up on HW only which isn't a major problem in cold weather but will be in the summer months so I need to resolve it soon.

Thanks for your help.

getmore4less

While you had it visible did you try the HW only and heating only to see/hear if was trying to work?

Jeepers_Creepers

Thanks for the update, Bel. I hadn't realised it was buried inside the boiler casing :-(

I hope the new head sorts it.

Belenus

getmore4less said:

While you had it visible did you try the HW only and heating only to see/hear if was trying to work?

Yes, but I couldn't really hear anything for certain. When the boiler starts up there is a noise from the boiler fan and the pump working so it is hard to hear any noise from the valve on top of that. I didn't want to have my hands in that area with power on and the boiler firing up so I couldn't feel for the valve moving either.

Bear in mind that this is not a normal situation with a boiler on a wall in a kitchen or other room and the pump and diverter valve easily accessible below it or in an airing cupboard. Everything is crammed into a large floor standing casing with a 150 litre HW tank behind the lower two white panels and the boiler, heat exchanger, pump, fan, diverter valve etc in the top section behind the upper smaller white panel. 

This youtube video of a similar boiler will give you some idea of what I am working with. The diverter valve is behind the control panel about level with the LED display and to the right and rear of that upper gas supply pipe. I had to get my hands in between various pipes and cables and to reach it. I could only just about twist it to the left to release it and it was even harder to get back on.

Emerging below the control panel the pipes are, left to right, hot water out from boiler via the 3 way valve to the CH radiators, gas supply in, hot water out from boiler via the 3 way valve to heat the HW storage tank, and the combined CH and HW return to the boiler so you can probably imagine how crowded it is behind that control panel.

Belenus

If anyone is interested, here is another video of this type of boiler with the panels removed.

From about 1:20 onwards, as the camera pans up and left, you can see below the large fan assembly, the grey actuator head with the black valve behind it and 3 copper pipes entering from the rear (from the boiler) and leaving left and right to the CH and HW.

Belenus

Five weeks on and the valve appears to have fixed itself.


I recently noticed that the radiators are no longer heating up on HW only.


I opened up the boiler again and now I can see the white indicator on the valve actuator head moving forwards and backwards as it should between HW and CH. Perhaps a bit of grit or foreign body that was causing the valve body to stick has been dislodged.

Anyway we can now have the HW on without the CH radiators also heating up which would have been a problem soon as the weather warms up.


A nice result for us. £42 DIY fix rather than £350 for Baxi.



Thanks to all who contributed with suggestions and advice.