Hot radiators when thermostat at zero...?

[saintgeorge]

Hi, I've got a weird problem I'm hoping someone can help me. When my timer comes on to heat my hot water, my radiators start heating up. This is despite the fact that:

(a) the timer is NOT also calling for heat (it's on 'TIMED' but the timings are not the same as for the hot water) and

(b) my hall thermostat is turned right down to zero.

Obviously if I close the radiator valves this problem doesn't occur!

It seems very strange and I can't think what might be causing it. The three way valve looks OK externally on visual inspection (the little lever is all the way over to the left on AUTO).

Any help appreciated.

 

[Agile]

Does the indicator on the valve move when you select HW only and then CH only?

If not then it may be failed or jammed.

Tony

 

[stardanny]

3 port valve might be jammed in mid position.

Lever might showing auto but when powering up, it will not move lever but the valve do.

What make is the 3 port valve? Is it a silver looking box?

Switch on hot water only and if boiler run, check play on lever, if it can move to man without resisit, then valve might be stuck.

Dan.

 

[saintgeorge]

Hi guys, thanks for that. The answers are:

1. It's a Honeywell silver-looking box about 50mm x 50 mm x 80 mm mounted on the top of a T-shaped junction. I had it replaced about 3 years ago, but the problem I'm experiencing isn't that old.

2. When CH on, HW off, radiator valves open and thermostat up to maximum, the lever on the box doesn't move - it stays over to the left on AUTO.

3. Similarly, with HW on, CH off, radiator valves off and thermostat down to minimum, the lever on the box doesn't move. Indeed, it never seems to move at all.

4. With HW on, the lever can quite easily be pushed over to the right (MAN/OPEN). There's no resistance or spring action.

Does that help at all? Any further advice appreciated.

 

[seco services]

2. When CH on, HW off, radiator valves open and thermostat up to maximum, the lever on the box doesn't move - it stays over to the left on AUTO.

The lever should be floppy no resistance.

3. Similarly, with HW on, CH off, radiator valves off and thermostat down to minimum, the lever on the box doesn't move. Indeed, it never seems to move at all.

The lever should have resistance.

4. With HW on, the lever can quite easily be pushed over to the right (MAN/OPEN). There's no resistance or spring action.

Thats not right it should have resistance when pushed across and return with the spring.
Providing the cyl stats calling for heat.