No hot water

[DTBPlumbing]

Hi I'm working on an unvented heat only system. The heating works fine as i serviced the boiler but the Honeywell motorised valve in the airing cupboard upstairs wont open, even when just the water is selected on the controls in the kitchen.
The property is unoccupied at the moment so the tank is cold.

I think its the actuator that needs replacing, but could it be something else. I pray its not an electrical fault as this isn't my forte!

When i was calling for the valve to open i would open the arm on the valve but it would just close again.

 

[Simon F]

welcome to the forum DTB,
is i t a 3 port valve?
could be the valve, but could be a fault with the controller or cylinder stat.
you will need to test where the power is when calling for hot water

 

[DTBPlumbing]

Its a two port valve. When i turn the immersion on at the wall you can hear it going so would that rule out the cylinder stat?
How would you go about testing where the power is when calling for hot water?

 

[secret squirrel]

you need to get yourself a wiring diagram and an electrical tester, sit there and go through it all. Its the only way. If the immersion heater is working they have there own stat so it won't be using the cylinder stat.

You could assume that it was all working and change the 2 port valve anyway.

Not the most professional but it is probably the valve, maybe....

 

[DTBPlumbing]

Think i need to go on a day course or something on how to use a tester with regards to plumbing controls.
I've got no electrical knowledge at all really and i cant help thinking its really gonna hold me back.

 

[kirkgas]

Zone valves have a manual over-ride button, if you manually open the valve and lock the lever into the slot and the boiler fires then its the actuator not operating properly
If it doesn't fire the boiler you will need to start checking connections to see what has power when the water is called for, its quite logical but TBH your competence is low so please be careful

 

[Megaflo-Experts]

Zone valves have a manual over-ride button, if you manually open the valve and lock the lever into the slot and the boiler fires then its the actuator not operating properly

I don't think manually opening the zone valve triggers the micro switch, which powers up the boiler/pump.

 

[Simon F]

www.[B]honeywell[/B]uk.com/documents/.../wiring%20guide%20issue%2016....[FONT=arial, sans-serif]‎[/FONT]

[FONT=arial, sans-serif]you can download a wiring guide easy enough.[/FONT]
[FONT=arial, sans-serif]a two port is straight forward.
grey should be permanent live
blue - neutral
green - earth
the brown wire gets the call for heat from programmer/stat, this then powers the motor,
when the valve is fully open this trips the micro switch which then allows power from the grey wire to power the orange wire.

so if you have 240 volts at the brown wire (and grey wire) but nothing at the orange wire then its the motor/valve.
if there is no power to the brown then the fault is before the valve. [/FONT]

 

[DTBPlumbing]

Very helpful, thanks all. Need to get myself a tester and learn how to use it, shouldn't be too hard learning the basics to start with.
I can replace the actuator and take it back to the merchants if that isn't the problem. I know another plumber with the electrical knowledge, so i can get him in if that fails.

 

[lame plumber]

go onto amazon and look up john reginald and central heating sounds like you need to have a read

 

[stevetheplumber]

you need to confirm there live and neutral to the actuator when hot water demand is calling

 

[DTBPlumbing]

Theres no clicking when i adjust the cylinder stat so im thinking that's the offending article.

 

[PlumbBobBob]

not necessarily

 

[DTBPlumbing]

Completed the job, thanks all. It was the actuator, I installed it after trying the stat from my cylinder at home which was the same.
Good feeling when it fired up at the end!

 

[kirkgas]

I don't think manually opening the zone valve triggers the micro switch, which powers up the boiler/pump.

If its not fully opening then manually opening it can make the connection to fire the boiler, its a good way to get the heating or hot water on as a temp repair

 

[Megaflo-Experts]

If its not fully opening then manually opening it can make the connection to fire the boiler, its a good way to get the heating or hot water on as a temp repair

Thanks. I always thought that manually opening the valve (Honeywell ones) doesn't quite reach the micro switch, so will not call for heat. I have manually opened a valve when the pump is already running (triggered by another valve), top open up another circuit.

Next time, I'll try manually opening a valve to see if it starts up the boiler/pump.