Faulty heating system

[sue_x]

Hi,

We've been having some problems with our central heating which was rectified temporarily with the replacement of the 3 way valve and the control programmer (Horstmann Tiara). We were told that the boiler itself (Ideal Mexico II) is OK if getting on a bit.

2 months on and the problem is back - both the hot water and central heating pick and choose when they want to come on and there doesn't seem to be a pattern as to which controls I switch on and which position the valve is in. If I move positions, sometimes it resists, sometimes not. Additionally, some radiators work better than others - they were all bled and were working perfectly when the repair was carried out.

The valve gets extremely hot when the programmer controls are on (we're not leaving them on excessively) which I suspect has caused it to burn out as the previous one had. Is it meant to get hot and if not is there something that can be done about it?

I'm consulting the group as we've had a succession of plumbers in our house due to this and am losing faith.

Thanks!

[Christian McArdle]

Personally, I think 3 port valves are a PITA. If I came across such a system causing trouble, I would convert to S-Plan, which is more reliable and MUCH easier to diagnose problems with. There are issues, however, such as needing a bypass valve, which might have to be manual for the ancient Mexico if it doesn't have overheat protection.

Christian.

[<me9]

I would echo that. I had 3 port valves (used instead of 2 port as my supplier had run out of them) for about 5 years. They gave endless trouble with intermittent micro-switches (easily changed for next to nothing) but I got fed up with changing them and have changed to S+ plan with no failures in another 5 years. My boiler had built in bypass, but an external one was fitted additionally near the 2 port valves.