No Central Heating without HW being on at same time

[00db]

I have recently replaced my old single channel timer with a 2 channel timer.

when the CH comes on at a seperate time to the HW, the timer only activates the CH Pump and doesn't fire up the boiler.

Any ideas?

If I turn up and down the room thermostat it just switches the CH pump on and off.

 

[corgiman]

because you have a very old system (part gravity part pump) you all ways have the hot water heating up

to have independance you must fit zone valves (mid position or two port)

just changing the timer will not do it

 

[00db]

so i should just set the HW and CH to come on and off at the same time for a cheap (or free!) fix?