Heating, but no hot water

Hi,

Recently why Heating stopped to work, but I had hot water. After getting a plumber out, he said he replaced the motorized 3-port valve, but said he could not rewire the electrics for the valve, but he would could back the next day with an electrician to finish the job, and he has never been seen since, the word cow and boy spring to mind.

After he left, I noticed that the problem had reversed: no hot water, but heating was/is working fine. I am very confused about what the problem could be. After reading other posts I see that no heating, but hot water is usually the motorized valve, but could that be reversed and is there any way to test this device?

Any information regarding the problem and the potential cost to fix it would be greatly appreciated.


Additional Info:

The motorized valve sits on top of a T-junction, which is label A, AB and B. AB goes to, or from, the pump. B goes to the tank. and A goes down into the floorboards.

The valve itself is a Siemens 3PMP-V22.

Valve is the right way round, so presumably wires aren't.
If you latch the valve onto the "man" poisition you'll get CH + HW whenever either should be on - probably - depending what's been done exactly...

ChrisR said:

Valve is the right way round, so presumably wires aren't.
If you latch the valve onto the "man" poisition you'll get CH + HW whenever either should be on - probably - depending what's been done exactly...

Click to expand...

If it hasnt been wired in yet I would say that the valve is the wrong way round
Are the wires connected yet then

UPDATE....

The wire were not connected, however I checked the junction box, where the central heating electrics are, and the motorized connections were labeled, so I connected them and the system works, sort of! The only problem now is that the programmer and system are backwards.

When I switch the programmer to water only, I get heating and water. Switching the programmer to heating and water I get heating only. Could this mean the the motorized head on the valve is the wrong way round? Or is wired incorrectly? Excuse my ignorance.

The programmer is a Randall 102. It has three switches: off, HW only, HW and CH.

Just out of interest how much does a new motorized head for the 3 port t-junction cost? And also is replacing the programmer a major job or just a case of wiring it correctly? Could anyone suggest any good literature of heating systems?

Any response is greatly appreciated

The wiring is still wrong. You could change the programmer but will need a decent understanding of system electrics to wire it in unless you can understand the Manufacturers disgrams.
Main thing is that unless you have a spare wire you will never get Central heating only as that clock does not have a DHW OFF LIVE.

Stan

Hi Thanks for the response.

Previous to the system going pear-shaped I had two options (excluding off):
- Hot water only
- Hot water and Heating

then the system broke, and I could only get hot water regardless what switch I put the programmer on.

Then the plumber came and said he replaced the motorized head, but he left the wires for the motorized valve disconnected. This left me with heating only, regardless of the switch. That made me think, with my limited knowledge of system, that he put the motorized head on the wrong way.

Today I checked the junction box and I connected the motorized head to it's label connectors. Now the control gives the opposite values, i.e.

Control Switched To --> Actual Effect
--------------------------------------------
Water Only --> Heating Only
Heating and water --> Heating and Water


Hope this helps clear up the confusion