boiler not always kicking in for ch needs

[sip1080]

Recently moved into a new house (that is new to me rather than brand new). Having a few CH issues.

1st of the Honeywell 3 position valve needed replacing (rads only hot when hot water was in need). Now the system does not always seem to respond to the room stat consistently. We do get stat triggered heating sometimes. However, this evening being a case in point the rads were cold the room stat should have been demanding the boiler fire and the control unit was set to hot water and CH 24 7.

I'm preempting any major fault finding (my multi meter is at work).

Any suggestions about the likely cause and the most effective method of fault finding this.

I appreciate I have not given many system particulars I am gathering that info now and will post it up on due course.

All help is massively appreciated[/quote]

 

[Agile]

Well its difficult to see what you expect us to tell you.

Any fault finding needs a test meter and knowing how to use it!

Tony

 

[DP]

You have a three port valve and also say that heating only works when hot water is on.

Valve will most likely be in manual open position to heat rads when you call for HW. If HW cylinder satisfied, you get no heating even if room thermostat clicks.

Check the sychron motor in the valve.

 

[sip1080]

Cheers for the help so far I will check the valve tonight.

Re what assistance I am after. It is my understanding that armed with a multi metre and the right knowledge about the system it is possible to check that each of the electrical components are working properly.

I am looking for guidance on what voltages I should be expecting to see at the room stat, tank stat and 3way valve under normal operation.

Cheers

Si

 

[DP]

You will see 240 on white wire at the valve when thermostat clicks ON and CH calling at the programmer.

 

[D_Hailsham]

Bring your meter home from work; then follow the instructions in How a mid-position valve works