Rubber balls in three port valves...

[John Rumm]

Hi,

Had some feedback on the wiki/faq that mentioned:

"Hi John, I enjoyed reading the article on the operation of the 3 port valve which was just up my street. You may be interested to know that the rubber ball inside sometimes swells up to more than twice it's normal size and block's port A & B and prevents circulation so before replacing the actuator make sure the shaft can be moved back and forth, it only moves about 1/2" each way but it proves the ball has not swollen. A service kit is available which includes the innard's of the valve. I blame all the different addative's that get added into the system and the incorrect doses of the same. I have laso known this swelling happen to the rubber seals inside diverter valves on combi boiler's etc. preventing their correct operation. Hope this info is of some use to you and your reader's"

Debating on where would be appropriate to include this. Does anyone know which brand / type of valve includes a ball of this type? (never taken the wet bit of one apart before!)

[geoff]

In message , John Rumm writes

Older Honeywell valves had balls which were later replaced with a paddle

I don't think that swelling up is much of a common problem - what causes the rubber ball to swell? ... some pratt spraying it with WD40 ? I can't see which proprietary additive would be absorbed by rubber

Where's Ed when you need him ?

[Scott M]

White lithium grease. I've found. Oops ;-)

Though it wasn't a 3-port valve but some rubber seals in one of those Aqualisa motorised shower pumps. Now have tube of plumbing lubricant.

[Onetap]

Fernox MB-1 used to, allegedly, but they've sorted that problem.

The inhibitor could/should stay in the system for several years, so it may still show up.