Hot water but no heating

[indus]

Hi, hoping somebody can help. (this is on behalf of somebody else)

The system is

1) Vaillant ecoMax pro combi

and then this

and a hand held remote controller like this

There is hot water but no central heating. When I checked the RF controller it seemed like it had been inadvertently set to a night mode denoted by a crescent moon.

I thought I'd reset it and it read a room temp of 22degs and I increased the required temp to 25degrees and the flame symbol appeared which I took to mean it would fire up.

But a couple of hours later and the rads are still cold.

Anybody have any ideas what the issue might be?

Many thanks

 

[MANDATE]

It would appear you have a 3 port mid position valve.
I would suspect that the valve is not operating as it should.
This could be related to the valve motor or micro switches in the valve head. On the other hand the valve may be OK and it is not receiving any power from the room stat.
The valve has five wires and the room stat makes the 'white' wire live. So that would be the first thing to check when CH is selected.

 

[indus]

Thanks Mandate.

Can you point out where the 3 port valve is please?

Also, if

1) The RF controller displays a 'flame' symbol

AND

2) The receiver unit isn't showing a red LED to signify it can't pick up a signal

Can I 100% assume that the problem lies somewhere further down the chain, or in other words it isn't an error I've made with setting the controller?

Thanks

 

[seco services]

The 3 port valve is the white valve at base of cylinder

Turn hw off ch on only
Look on the side of the valve you'll see a marker labeled W - M - H
whats the marker pointing to ?

 

[indus]

The 3 port valve is the white valve at base of cylinder

Turn hw off ch on only
Look on the side of the valve you'll see a marker labeled W - M - H
whats the marker pointing to ?

Thanks Seco.

To turn hw off I presume I use the device that is seen in the second pic that is called 'Ikon' ?

Thanks again

 

[MANDATE]

The place to carry out the testing is in the terminal box which is your white box with yellow label.
There will of course be live wires so care is needed.
The motorised valve has the black cable with 5 wires going into terminal box. The wires are white,grey,orange,blue and green/yellow.
With power to the boiler on and HW and CH off only the grey wire from the 5 should have 230v.
The programmer/timer switches power to the room stat. Then the room stat switches on the power to the 'white' wire of valve.

With CH switched on test the white wire.
If 230v is present programmer/timer and room stat are operating correctly and problem is the mid position valve.
If 230v is not there then problem is further back at room stat or even further back at programmer/timer.
Briefly the valve needs 230v on the white to move valve to mid position. Then the grey wire comes into action with 230v to take over from the white. It drives motor/valve over last half of range and triggers micro switch to allow 230v out of the 'orange'wire to operate boiler.
Not with HW only or HW/CH the boiler is operated through the cylinder stat and does not rely on valve.

 

[indus]

Mandate, thanks for such a detailed explanation. One thing confuses me, you talk about three components in the chain ie the programmer/timer, the room stat and the valve itself.

Isn't my Drayton digistat RF3 both the programmer/timer and room stat all in one device?

Thanks

 

[indus]

Ok, I've figured out that the device marked 'Ikon' is the actual programmer. What piece of kit do I need to test for 230v in the terminal box? Can I just use one of those screw drivers with a light on the end??

 

[Terry7556]

no because it does not measure how much, like a multimeter.
think its time you called someone in to sort it out, be a lot quicker

 

[indus]

Thanks Terrence, tbh carrying out that sort of testing was always probably going to be beyond me.

However I rang up the Drayton helpline and they offered some simple advice to help get to the bottom of things

1) Ensure flame symbol present on remote.

2) If flame present but no green led on receiver then either remote or receiver faulty.

3) If green led appears on receiver shuffle the temp on the remote up and down and listen for the relay to click in the receiver. If it doesn't click it means it is receiving the signal but it's relay is faulty

 

[Terry7556]

is any of that occuring?

 

[indus]

is any of that occuring?

I need to check all that tonight after I get home from work