I was beginning to think that myself; it's the only logical explanation.
Getting HW when only CH is on and it's not the valve???
- Thread starter ragj195
- Start date
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Oh no. CH only on HW off makes the left bathroom rad valve heat up first. HW only on makes the right bathroom rad valve heat up first. The fact that HW only always heats the same side rad valves as CH only suggest that the return of the bathroom rad is plumbed into the CH flow not return 
Don't you mean opposite side?Oh no. CH only on HW off makes the left bathroom rad valve heat up first. HW only on makes the right bathroom rad valve heat up first. The fact that HW only always heats the same side rad valves as CH only suggest that the return of the bathroom rad is plumbed into the CH flow not return
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Got you.
The problem now is: what to do next?
It all depends on how important it is to have the bathroom rad working all year round.
One thought.
Are you able to check the return from the cylinder back to the boiler?
It should be plumbed like this:
View media item 73253
There should be no connections between the cylinder connection and the boiler.
Yeah that diagram looks right and matches the photo at the top of page two.
I know I am now at a point where nothing can be done without ripping things up. If I close the 15mm isolation valve on the pipe to the bathroom rad in the summer, that will stop HW heating the rads but will also mean I lose that rad in the summer which isn't really a problem. HW only heating up other rads in the winter isn't much of a problem as it normally co-incides with CH being on anyway.
So, this may well be my last post. Thanks for your help it's really appreciated. You've given me some fault finding tips that I never would have thought off.
I know I am now at a point where nothing can be done without ripping things up. If I close the 15mm isolation valve on the pipe to the bathroom rad in the summer, that will stop HW heating the rads but will also mean I lose that rad in the summer which isn't really a problem. HW only heating up other rads in the winter isn't much of a problem as it normally co-incides with CH being on anyway.
So, this may well be my last post. Thanks for your help it's really appreciated. You've given me some fault finding tips that I never would have thought off.
I had forgotten that pic.
One possible solution is to disconnect the 15mm pipe from just after the HW valve and connect it to the CH return just before it connects to the boiler. The bathroom rad would then be part of the CH circuit only. The rad "return", currently connected to the CH flow, would then become the "flow"; and the "flow" would become the "return".
C
chantelle
Av a look, can`t be bothered to explain:
Why is Reverse Circulation occurring?
The main cause of reverse circulation is normally created when pipework is incorrectly fitted, when the 'Three T Rule' being ignored by lazy or incompetent installers or can simply be caused by a a zone valve letting by or seizing.
Incorrect Pipework
When pipework is fitted incorrectly by lazy or incompetent persons the flow of the water to the hot water cylinder can also travel into the heating system allowing one or two radiators to heat up.
This is very simple to avoid by ensuring that last tee back to the boiler is from the hot water circuit, not the radiator circuit.
The 'Three T Rule'
The simple 3-T Rule shows how the various take-off and return T's should be connected in order to avoid costly problems and call-backs arising from incorrect system circulation.
From the boiler, the correct order of the pairs of flow and return T's is as follows:-
1) Vent and Cold Feed
2) DHW Cylinder
3) Radiators (zone 1)
Where there are additional heating zones, the same simple logic applies, i.e. heating zone two – 4th pair of T's; heating zone three – 5th pair of T's.
Faulty Zone Valve
If a Zone valve is faulty you could be experiencing hot radiators all year round or no heat at all. This situation needs to be rectified by a qualified heating engineer who can diagnose the fault and change the faulty valve.
Some systems of valves are more prone to seize then others, particularly the 'Y Plan' system and it can be advisable to change this to a 'S Plan' to avoid future call backs.
Back to Top
Why is my bathroom radiator \ towel rail hot all of the time?
Thousands of UK households have a bathroom radiator or towel rail permanently heated by design and necessity so it is not always a problem when this occurs.
The simple reason that many people like to keep the radiator on in the bathroom is to keep towels dry and keep the floor free from moisture. This may not be the most energy efficient lifestyle choice but it is present in many homes in the UK.
More importantly, many heating and hot water systems require a bypass fitted to dispel heat from the boiler and installers use the bathroom radiator as a simple yet effective way of dispersing the heat which in turn keeps the bathroom radiator or towel rail warm for a period of time and keeps the boiler in good shape and in warranty.
Back to Top
What can you do about Reverse Circulation?
Fortunately qualified heating engineers can diagnose and solve reverse circulation issues
A faulty zone valve can be changed for a new one, the system can also be upgraded if preferred by the customer.
The 'Three T Rule' can be incorporated into an existing system by a competent installer. This may involve new pipework being run, dependant on how badly the original installation was fitted by a previous engineer.
A simple 'non-return valve' can be fitted to the offending pipework to stop reverse circulation occurring. This will solve the problem but should only be seen as a 'quick fix' and the reasons for the reverse circulation occurring in the first place should still be investigated as normally there will be other errors.
Other, more serious errors can lead to poor efficiency, water and gas wastage and much more dangerous issues such as scalding and system failure. It is normally the instalations that have minor faults that also develop major faults.
Bing bang, Billy Bish Bosh..Sorted.
Why is Reverse Circulation occurring?
The main cause of reverse circulation is normally created when pipework is incorrectly fitted, when the 'Three T Rule' being ignored by lazy or incompetent installers or can simply be caused by a a zone valve letting by or seizing.
Incorrect Pipework
When pipework is fitted incorrectly by lazy or incompetent persons the flow of the water to the hot water cylinder can also travel into the heating system allowing one or two radiators to heat up.
This is very simple to avoid by ensuring that last tee back to the boiler is from the hot water circuit, not the radiator circuit.
The 'Three T Rule'
The simple 3-T Rule shows how the various take-off and return T's should be connected in order to avoid costly problems and call-backs arising from incorrect system circulation.
From the boiler, the correct order of the pairs of flow and return T's is as follows:-
1) Vent and Cold Feed
2) DHW Cylinder
3) Radiators (zone 1)
Where there are additional heating zones, the same simple logic applies, i.e. heating zone two – 4th pair of T's; heating zone three – 5th pair of T's.
Faulty Zone Valve
If a Zone valve is faulty you could be experiencing hot radiators all year round or no heat at all. This situation needs to be rectified by a qualified heating engineer who can diagnose the fault and change the faulty valve.
Some systems of valves are more prone to seize then others, particularly the 'Y Plan' system and it can be advisable to change this to a 'S Plan' to avoid future call backs.
Back to Top
Why is my bathroom radiator \ towel rail hot all of the time?
Thousands of UK households have a bathroom radiator or towel rail permanently heated by design and necessity so it is not always a problem when this occurs.
The simple reason that many people like to keep the radiator on in the bathroom is to keep towels dry and keep the floor free from moisture. This may not be the most energy efficient lifestyle choice but it is present in many homes in the UK.
More importantly, many heating and hot water systems require a bypass fitted to dispel heat from the boiler and installers use the bathroom radiator as a simple yet effective way of dispersing the heat which in turn keeps the bathroom radiator or towel rail warm for a period of time and keeps the boiler in good shape and in warranty.
Back to Top
What can you do about Reverse Circulation?
Fortunately qualified heating engineers can diagnose and solve reverse circulation issues
A faulty zone valve can be changed for a new one, the system can also be upgraded if preferred by the customer.
The 'Three T Rule' can be incorporated into an existing system by a competent installer. This may involve new pipework being run, dependant on how badly the original installation was fitted by a previous engineer.
A simple 'non-return valve' can be fitted to the offending pipework to stop reverse circulation occurring. This will solve the problem but should only be seen as a 'quick fix' and the reasons for the reverse circulation occurring in the first place should still be investigated as normally there will be other errors.
Other, more serious errors can lead to poor efficiency, water and gas wastage and much more dangerous issues such as scalding and system failure. It is normally the instalations that have minor faults that also develop major faults.
Bing bang, Billy Bish Bosh..Sorted.
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