CH on but not on Programmer

[littlelegs]

Just returned from holiday and set the CH/HW programmer to HW to get ready to have a nice bath.
After about 20 mins the wife said that the radiators were hot and that the CH was on. Went to the kitchen and the CH/HW programmer only had the HW side activated, display showed CH as OFF but the CH radiators were most certainly getting hot , except the one in the bathroom which is the one that normally gets warm when the HW is on.

From the documentation we have the setup is

Baxi Solo 2 50PF boiler
ACL Lifestyle LP722 Programmer
Honeywell T6360/4360 thermostat
Honeywell V4073A Motorised mid position valve
Grundfos domestic circulator

I have set the Honeywell T6360/4360 thermostat to minimum and the valves on the radiators to * (Frost) to minimise the temperature.

Any ideas as to why the CH is coming on?

 

[seco services]

Is the water heating ? or just the rads ?
sounds like the valves possibly stuck in ch position.

 

[littlelegs]

Water heats up fine ..... but so did the rads.
By settings the thermostat and the rad valves we seem to have reduced the amount of heat they are emitting ( as you would expect ! )

 

[45yearsagasman]

Get the 3 port valve sorted as SS suggested.

 

[littlelegs]

got a three wave valve and a plumber to fit - all sorted


Many thanks for the info .......

 

[seco services]

got a three wave valve