Radiators not heating

[iShaun]

Hi guys

Wondering if someone has an idea to my issue even my plumber doesn't know why.
Firstly, the boiler is about 3 years old (moved into new house Sept 2019). The boiler is absolutely fine. I'm getting hot water to all taps and showers, so we can rule the boiler out.
I have 2 central heating zones (downstairs & upstairs) with 2 separate thermostats and 2 separate zone valves (which are behind the bath panel in the bathroom).
The problem is, when I turn the thermostats on, nothing happens anymore. The boiler doesn't fire up and I get no heating whatsoever.
The zone valves' levers do not switch to open the valves.
I've put the valves in manual so they're always open but this makes no difference so I don't think it's the valves?

Any idea?

 

[Exedon]

You need a multimeter (and be competent to use it)
Should be easy to see if power to valve's or not.
On most motorised valves moving leaver to manual will not trigger them.

 

[terryplumb]

What thermostats / programmer do you have ?
Did both zones fail at the same time ?

 

[CBW]

The boiler is definitely set to heating and hot water? Some have a selector knob to change between hot water only or heating and hot water.

 

[iShaun]

The boiler is definitely set to heating and hot water? Some have a selector knob to change between hot water only or heating and hot water.

Yes, nothing on the boiler has been changed. Mine has a selector knob both are selected. I've tried resetting the boiler but that made no difference.

 

[iShaun]

What thermostats / programmer do you have ?
Did both zones fail at the same time ?

They are fixed to the wall and are dials.
Downstairs failed first, so was leaving downstairs valve in manual so when I turned upstairs heating on it heating both upstairs and downstairs.
But now the upstairs valve doesn't automatically switch open. So now both valves are in manual but I'm not getting heating at all.

 

[terryplumb]

Sounds like both zone valves have failed ,probably their motors.
What provides your hot water ,is it from a storage cylinder with its own motorised valve ?

 

[iShaun]

Sounds like both zone valves have failed ,probably their motors.
What provides your hot water ,is it from a storage cylinder with its own motorised valve ?

I have a combi boiler, no storage.
Even if the valves are manually open could it still be the valves which are the issue?
Could it be anything to do with the little black box where the valves are connected to?

 

[terryplumb]

It's the motorised valve that sends voltage to the boiler to fire up.
What little black box ? Show us a pic.

 

[iShaun]

It's the motorised valve that sends voltage to the boiler to fire up.
What little black box ? Show us a pic.

 

[terryplumb]

Ok ,that's just a junction box used as a wiring centre where all the electrical connections are made.

 

[iShaun]

Ok ,that's just a junction box used as a wiring centre where all the electrical connections are made.

Ahh, okay. So all signs are pointing to the zone valves which will need replacing?

 

[terryplumb]

Yes ,probably just their motors. What make and model are they ,look like Honeywell ?

 

[iShaun]

A plumber looked at them a bit ago but I wasn't convinced the valves were the problem. I can't think of the name but it begins with a "T", and he said I have to replace like for like due to how many wires there are in the valves.

 

[terryplumb]

Probably a cheap copy of a Honeywell.