Strange heating/hot water problem - any ideas?

[creeper]

Hi all, I have a strange problem with a heating system and was looking for some advice as to what's wrong.
The boiler is a Baxi with a Honeywell room stat and ST799A1003 timer.
both motorised valves by the hot water tank operate, but the heating will not come on unless the hot water is on as well on the timer, my understanding is the hot water and the heating should be able to be on independently.
I know the boiler was moved a few years ago when the kitchen was refurbished and was wondering if whoever did that wired up something wrong - possibly in the timer?
Cheers for any help overcoming this annoying problem.

 

[PlumbBobBob]

are the two port valves on the same pipe? thus requiring both to be energised for heating to work.

 

[ecowarm]

Timer not set correctly sounds like its set for gravity hot water, so you have to have H/W on at the same time

 

[creeper]

are the two port valves on the same pipe? thus requiring both to be energised for heating to work.

valves are on different pipes.

Timer not set correctly sounds like its set for gravity hot water, so you have to have H/W on at the same time

is there a simple way to check this?

 

[creeper]

Having looked at the install diagrams here > http://products.ecc.emea.honeywell.com/europe/pdf/en0r8440uk07r0101.pdf I'm guessing it should be the Sundial S plan that I should have?
If so where would the terminal block labled 1-10 usually be located?
Cheers

 

[dontknowitall]

Oblong white plastic box around 5" by 4" (give or take). Usually near zone valves and pump (and if vented system) then usually in the airing cupboard.