2 faulty motorised valves?

[Kevine]

Hello,
I have an issue with rads getting hot when turning water on only.
I have 2x 2 port motorised valves and running some tests.
I've took the heads off both valves.
Rad motor seems to turn when i switch rads on
Water motor seems to make an off clicking noise from motor so i suspect this could be faulty.

I am hoping that the motor is the fault and not the valves that would turn this into a big job.
But with the heads off both valves, it seems when i manually turn the spindle on either valve, hot water seems to travel through. I'm only testing this by touch, so firing up the boiler appears to make both sides of the valves hot even when i turn the spindle. Although turning the spindle not clear which is the shut position.

Could it be just bad luck and i have 2 faulty valves plus at least 1 faulty head?

Furthermore, i don't seem to have a drain point in my central heating system. Any ideas how best to drain the system with no drain valve?
I have a closed pressurised system.

Many thanks!
Kevin

 

[terryplumb]

If hot water only is selected,and the radiators heat then it's likely that the heating zone valve is passing.Turn the electric supply off to your system,remove the actuator head from the heating zone valve. Turn electrics back on and select hot water only ,if radiators continue to heat replace the complete zone valve for central heating.

 

[fixitflav]

Hello,
I have an issue with rads getting hot when turning water on only.
I have 2x 2 port motorised valves and running some tests.
I've took the heads off both valves.
Rad motor seems to turn when i switch rads on
Water motor seems to make an off clicking noise from motor so i suspect this could be faulty.

I am hoping that the motor is the fault and not the valves that would turn this into a big job.
But with the heads off both valves, it seems when i manually turn the spindle on either valve, hot water seems to travel through. I'm only testing this by touch, so firing up the boiler appears to make both sides of the valves hot even when i turn the spindle. Although turning the spindle not clear which is the shut position.

Could it be just bad luck and i have 2 faulty valves plus at least 1 faulty head?

Furthermore, i don't seem to have a drain point in my central heating system. Any ideas how best to drain the system with no drain valve?
I have a closed pressurised system.

Many thanks!
Kevin

Is it a new problem, or have you just moved in, or had work done, or what?

 

[CBW]

Could it be that the 3 tee rule has been broken and you’re getting some reverse circulation?

 

[Kevine]

Is it a new problem, or have you just moved in, or had work done, or what?

No work done, been in about a year so suspect it was same as when moved in

 

[fixitflav]

No work done, been in about a year so suspect it was same as when moved in

Then it could be a piping problem, as CBW suggested. All the heating return pipes must be commoned before joining the cylinder return. Been discussed several times on this forum.

 

[Kevine]

Then it could be a piping problem, as CBW suggested. All the heating return pipes must be commoned before joining the cylinder return. Been discussed several times on this forum.

Thanks. Is there an easy way to identify a piping problem?
If best to just search forum will do that. But thought I'd ask first for a pointer
Thanks

 

[CBW]

Start with the system cold, turn hot water on and feel the pipe on the outlet side of the heating valve to confirm it’s not letting by. Then if that’s ok, then it just becomes detective work, finding where the tee lies so it can be altered.

 

[fixitflav]

Thanks. Is there an easy way to identify a piping problem?
If best to just search forum will do that. But thought I'd ask first for a pointer
Thanks

If it's a typical house the upstairs rad returns will be joined and brought to near the boiler, similar for the downstairs, the two commoned, with the cylinder return coming in after. So if there's a pipe teed into the cylinder return before that, eg in the airing cupboard, there's a good chance it's piped wrong.
That's after checking for a passing valve à la CBW, of course.

 

[Kevine]

If it's a typical house the upstairs rad returns will be joined and brought to near the boiler, similar for the downstairs, the two commoned, with the cylinder return coming in after. So if there's a pipe teed into the cylinder return before that, eg in the airing cupboard, there's a good chance it's piped wrong.
That's after checking for a passing valve à la CBW, of course.

Attaching here a picture of the valves near the cylinder. I can see at least 2 tees here, does that help?
Thanks

 

[Johntheo5]

Is the TF1 on the boiler flow or return?.

 

[Kevine]

Is the TF1 on the boiler flow or return?

Think it's the flow as the motorised valves are after it.
Not an expert though.
Thanks

 

[fixitflav]

Attaching here a picture of the valves near the cylinder. I can see at least 2 tees here, does that help?
Thanks

Not easy to tell from the photo, but if to the bottom right, the tee into the cylinder return pipe is from the upstairs rads, it looks dodgy. Needs a bit of detective work!
Did the passing valve test come up with anything?

 

[Johntheo5]

This may explain your problem if only occuring with DHW on.

 

[fixitflav]

Think it's the flow as the motorised valves are after it.
Not an expert though.
Thanks

Any developments? Interested to know how it went.