Hot water, but cold radiators or cold water, but hot radiato

[teuscher1]

Last week my house was getting chilled so I turned turned on the central heating and my house warm up as expected. I then decided to turn on the hot water but to my surprise few hours later I noticed that I was not getting hot water in any tap.

Once the house warm up I turned off the heater and turned on the hot water and I started getting hot water again!! As a way of a test I turned on heater but non of the radiators warmed up.

So I concluded:
1.- In order to have hot water I have to turn off the heater
2.- In order to to have the heater I have to turn off the hot water
3.- Which ever service is turned on "first" works fine but not the second

Additionally I find very strange is that in the past when turning on or off the heater and/or hot water I used to hear a clear "click" coming from the programmer but with this recent problem I only hear the "click" which ever the first service is requested (hot water or heater) but not the second click for the other service. I do remember very well hearing both clicks in the past.

To try to fix this problem:
1- I have turned off and on the entire system for few minutes but the problem continues.
2- I have checked the system pressure to be around 1 bar
3- I have make sure the programmer is overridden so both water and heater are "on".

I have installed in my home:
- Boiler Remeha 30s avanta plus system in the kitchen
- a Honeywell programmer in the airing board
- a Honeywell thermostat downstairs
- 2 Honeywell motorized diverter valves model V4043H 1056
- an Unvented cylinder Ariston Primo HE ITI 250

I will appreciate if someone could give me a clue on what could be wrong with my system as unfortunately my installation is out of warranty .

 

[Agile]

There is clearly some problem. It sounds as if there is a programmer fault but that kind of fault would be very rare!

You can get both CH and HW until the fault is diagnosed by placing the manual lever on both valves to the locked open position.

Check the levers remain locked as they can unlock when powered to the on position.

Tony

 

[teuscher1]

Tony

Thanks for your reply.

I agree with you I don't think the programmer is the problem, I believe the problem are the diverted valves after being unused over the summer so can I ask you:

- Is there a way to identify if a diverted valve doesn't work?
- Is it common to replace the heads only? or has to be replaced the entire valve?

Also giving the type of system that I have am I correct in saying there is a pump somewhere? if so could my problem be related to the pump?

Thanks again

 

[Whitespirit66]

You can eliminate the programmer, if you have a multi meter. Turn both ch and hw on at the programmer, and test if you have 240V from the programmer's ch on and hw on terminals. These are usually terminals 4 and 3 on programmers.

 

[teuscher1]

Thanks

I have followed your instructions, the results with the multimeter are as follows: (please see the attachment diagram for numbers)

When both CH and HW are "off"

HW: 239v (6&2)
CH: 239v (6&3)

When both CH and HW are "on" but CH was turned "on" first

HW: 239v (6&2)
CH: NIL (6&3)

When both CH and HW are "on" but HW was turned "on" first

HW: NIL (6&2)
CH: 239v (6&3)

Would these mean the programmer is faulty?

Untitled

• teuscher1
• 1 Nov 2013
• 2