Here's an update...
For many years we've had the hot water set to 'all day', so from early morning until late at night. That means any time the heating is on the hot water is too.
Today I turned the cylinder coil valve from fully open (5 turns) to half way and switched the hot water to off for good measure.
With TRVs set to our normal operating mode (some fully open, some fully closed and the rest somewhere in-between) every downstairs radiator got hot. At last.
Now....... having read-up on Honeywell valves it seems that if all is well they should only open and let water through the coil when the hot water is switched to ON and there is a demand from the cylinder thermostat. The Honeywell in turn then switches on the boiler and pump. If this is the case then the hot water should only have an effect on the heating when the cylinder thermostat is calling for heat.
I remember about 10 years ago a BG engineer said the wiring in the airing cupboard was wrong and he had put it right.
I'm now wondering if he put something wrong that was previously right.
I checked the Honeywell and it was indeed closed (lever would only move a bit up the slot). I've switched the hot water on and the valve is now open (lever moves all the way in the slot). This is normal so far as the cylinder is calling for heat and the pump and boiler are on.
I'm going to wait until the boiler and pump switch off and make sure the valve is closed again. I'm sure it will be as it's the Honeywell that switches the boiler and pump on and off if I've read things right.
Ok... the boiler and pump are off and the Honeywell is closed (if I go by the fact the lever only manually moves a third of the way up the slot). If I turn the heating on the coil Honeywell stays closed so all ok there then.
If the Honeywell valve is working ok then water will only flow through the coil occasionally to top-up the water temp so I'm wondering if having the HW to on all day and the manual valve to the coil fully open as it was should affect the heating that much. The only other thing could be the valve not seating properly when it closes, thereby allowing some hot water through the coil all the time (like another by-pass).
Anyway, I'll leave the manual valve as it is and set the HW to only come on for a couple of hours in the morning and evening and try the heating from a cold start tomorrow with the TRVs set to normal conditions and see how things feel.
It's interesting stuff this and I'm learning a lot so thanks for all your inputs. Things are definitely looking up here.
Cheers for now.
For many years we've had the hot water set to 'all day', so from early morning until late at night. That means any time the heating is on the hot water is too.
Today I turned the cylinder coil valve from fully open (5 turns) to half way and switched the hot water to off for good measure.
With TRVs set to our normal operating mode (some fully open, some fully closed and the rest somewhere in-between) every downstairs radiator got hot. At last.
Now....... having read-up on Honeywell valves it seems that if all is well they should only open and let water through the coil when the hot water is switched to ON and there is a demand from the cylinder thermostat. The Honeywell in turn then switches on the boiler and pump. If this is the case then the hot water should only have an effect on the heating when the cylinder thermostat is calling for heat.
I remember about 10 years ago a BG engineer said the wiring in the airing cupboard was wrong and he had put it right.
I'm now wondering if he put something wrong that was previously right.
I checked the Honeywell and it was indeed closed (lever would only move a bit up the slot). I've switched the hot water on and the valve is now open (lever moves all the way in the slot). This is normal so far as the cylinder is calling for heat and the pump and boiler are on.
I'm going to wait until the boiler and pump switch off and make sure the valve is closed again. I'm sure it will be as it's the Honeywell that switches the boiler and pump on and off if I've read things right.
Ok... the boiler and pump are off and the Honeywell is closed (if I go by the fact the lever only manually moves a third of the way up the slot). If I turn the heating on the coil Honeywell stays closed so all ok there then.
If the Honeywell valve is working ok then water will only flow through the coil occasionally to top-up the water temp so I'm wondering if having the HW to on all day and the manual valve to the coil fully open as it was should affect the heating that much. The only other thing could be the valve not seating properly when it closes, thereby allowing some hot water through the coil all the time (like another by-pass).
Anyway, I'll leave the manual valve as it is and set the HW to only come on for a couple of hours in the morning and evening and try the heating from a cold start tomorrow with the TRVs set to normal conditions and see how things feel.
It's interesting stuff this and I'm learning a lot so thanks for all your inputs. Things are definitely looking up here.
Cheers for now.