Help with changing two port motorised powerhead

The_Abyss · 12 Apr 2020 at 21:56

I've three of these in our airing cupboard, controlling heating and hot water. We had a plumber change one of them a couple of months ago, running part of our central heating, as the motor had failed. Now the motor appears to have failed in the one controlling the valve for the hot water.

I've identified this https://www.screwfix.com/p/honeywel...-replacement-powerhead-22mm-compression/326fv as the correct replacement, and some research suggests that it is a simple swap. However, there are a couple of more alarming comments suggesting that some of the older units were not sealed off from the water, and cannot be swapped without draining the system and replacing the valve too. I can't see a way to identify what my current unit is, other than the original Honeywell part code which is V4043H1056.

Anyone with experience of these? Thanks in advance.

the_dead_parrot · 12 Apr 2020 at 22:06

The old style valves top removable case was completely flat. The valves with the changeable motorized head have a small circle bulge.

The_Abyss · 12 Apr 2020 at 22:10

the_dead_parrot said:
The old style valves top removable case was completely flat. The valves with the changeable motorized head have a small circle bulge.

You sir, I would buy a pint right now if I was able to, thank you. They all have the small circular bulge.

Many thanks!

Orionaut · 13 Apr 2020 at 08:44

Might be better to bite the bullet and replace them properly.

The last time I did this job I discoverer that the reason why the motor had failed was because the valve was shagged.

While you have the system drained down, fit some isolating valves so next time the job will be easier..

The_Abyss · 13 Apr 2020 at 10:24

Thanks, but I’m attempting to avoid draining the system. I guess I’ll find out if I need to once the motor is replaced!

The_Abyss · 15 Apr 2020 at 21:48

I hate it when people never finish off their threads.

In this case, it was a happy ending. Removing the old motor was fairly straightforward, just complicated by not being very accessible. The new unit had one more wire than the old one, but a quick Google revealed that it should just be sealed off and ignored. Hot water again shortly afterwards, hero status in my wife's eyes for approximately the duration of a hot shower, after which it was casually forgotten!

Burned_Alive · 16 Apr 2020 at 12:47

If it happens again you can manually open the valve using the lever. It has a catch so you can leave it open long enough for the cylinder to warm up without having to stand there.

The_Abyss · 16 Apr 2020 at 15:04

Thanks, I did try this but it didn't appear to be working.

Burned_Alive · 16 Apr 2020 at 17:20

The_Abyss said:
Thanks, I did try this but it didn't appear to be working.

When you've moved the lever to the open position, you have to pull the lever across and then while holding it across let it slide back slightly on the spring before it will catch and hold.

The_Abyss · 16 Apr 2020 at 17:38

Yeah, I did that but the spring felt too slack and didn't want to come back. It didn't seem to be damaged when I removed it, so perhaps it is a sign that the valve is on the way out.