Zone Valve not opening on demand

[something1965]

House - Heat Exchangers with 2 way Honeywell Zone Valves (about 18 years old).

On one exchanger the hot water stops flowing after the specified temp is reached.....so it appears.f

If I turn up the thermostat then no flow (cold pipe into exchanger).
If I turn the heat off then on again then no flow (cold pipe into exchanger).

If I turn off the heat then I get resistance from the valve lever.
If I rock the lever back and forth twice then the waters starts to flow.

What part of the valve would be faulty do you think?

Is there any other troubleshooting I need to do for more info?

Thanks

 

[stardanny]

This is a uk based forum, but I can help.

Sound like the motor inside is faulty.

You will need to check there is power to the motor when stat is turn up.

Daniel.

 

[something1965]

When the heat is turned on I no longer have resistance.

I should have added that part, does it mean I have power then?

Thanks

 

[jeff the gasman]

Probably the actuator head from what you say. End switch not proving.
I'd come and have a look if you pay air fares and accommodation.
Happy new year
Jeff

 

[TCCHeating]

Untitled

• TCCHeating
• 8 Nov 2014
• 2

Untitled

• TCCHeating
• 8 Nov 2014
• 2

Follow this guide. Youll need a multimeter.

If orange wire doesnt become live, but the valve opens. Then the microswitch in the valve is not activating. You may be able to change the head without draining. Removable heads have a round raised dimple on top of the head

 

[something1965]

Thanks mates...looks like enough to go on.

Will advise how I make out.

London born (Barnet)

Cheers and HNY

 

[something1965]

New intel....

24,7 volts when called for heat.

I noticed the Paddle indicator did move towards B, felt the pipe but no heat!
I moved the indicator more towards B , just a tad and it worked.

Does this indicate a bad motor or something else seizing up?

Thanks

 

[something1965]

Finally an update, I lost this forum link.
The balls inside the valves were deteriorating and the arms to the balls were in bad shape too....thinning out.