Central Heating comes on when only Hot water is on

[Deleted User]

Surely the power is off when it returns to closed by its spring

Honeywell does produce two versions of some of its valves: powered on and powered off.

inspectorperez

As molerat's earlier post, I have this issue from time to time and resolution is to move the lever from left to right two or three times. Mine is a Honeywell and I simply switch the boiler off before moving the lever. I find it has resistance going one way and then moves back of its own accord.

My valve is about 10 years old on a 34 year old Apollo Potterton Myson boiler which is still going strong.

oldagetraveller1

"Where was the lever positioned in your case? Mine is at the top (Auto) position where it has always been."

It was not quite in the "auto position" and would not return to that position. Even when operated manually a couple of times it would only spring back from the "emergency" heating and hot water, lock position to that same place each time. That resulted in the 3 way valve not closing off the heating outlet completely.

BG fitted the new head using some 5? wire plug and socket(ENSTO). That doesn't require accessing the connection box when(not if) it fails again.

 

Mister_G

oldagetraveller1 said:

"Where was the lever positioned in your case? Mine is at the top (Auto) position where it has always been."

It was not quite in the "auto position" and would not return to that position. Even when operated manually a couple of times it would only spring back from the "emergency" heating and hot water, lock position to that same place each time. That resulted in the 3 way valve not closing off the heating outlet completely.

BG fitted the new head using some 5? wire plug and socket(ENSTO). That doesn't require accessing the connection box when(not if) it fails again.

 

Not quite as sophisticated, but the same idea!

PennyForThem_2

I have this - radiators heat up when hot water comes on even if CH is off  (dual control - hive thermostat central hub) - and I see it as an advantage.  BUT only if you have individual radiator thermostats so you can totally turn off or limit heat up.

We inherited this set up when bought house late 1980s.  The radiators that heat are in kitchen, bathroom, and bedrooms (go figure) and one in the hall.  So other rooms - 3; 1 has 3 rads, others 1 each  - don't heat up.  I control it via the individual thermostats, sort of.

TBH it is weird, but not sure I would change it.  It has advantages.

P1Fanatic

PennyForThem_2 said:

I have this - radiators heat up when hot water comes on even if CH is off  (dual control - hive thermostat central hub) - and I see it as an advantage.  BUT only if you have individual radiator thermostats so you can totally turn off or limit heat up.

We inherited this set up when bought house late 1980s.  The radiators that heat are in kitchen, bathroom, and bedrooms (go figure) and one in the hall.  So other rooms - 3; 1 has 3 rads, others 1 each  - don't heat up.  I control it via the individual thermostats, sort of.

TBH it is weird, but not sure I would change it.  It has advantages.

We don't have TRVs on all our radiators so cant do that. I turned off the ones we can but I don't think that is a real solution. I am no heating expert (far from it) but surely you are still using extra gas to heat the heating circuit from the boiler to all the radiators anyway i.e. the pipe feeding your radiator will be hot even if the radiator itself isn't heating up as the TRV is turned down? Will test this theory later when the HW comes on.

PennyForThem_2

Umm maybe but in summer all rads turned off and CH off and won't get turned on until mid Nov  so don't really think pipes heating up will make that much difference.   

I am a very low user of gas and elec in a well insulated 4 bed detached and I have always gone with heat the human -  my children laugh because they too have learnt that when home wrap up.

nadsat

[Deleted User] said:

Surely the power is off when it returns to closed by its spring

Honeywell does produce two versions of some of its valves: powered on and powered off.

Got a ref? I can't see why you'd power the valve to stay closed. I know there are some applications that fail in the open position though so maybe that's it but not applicable to most systems. 

P1Fanatic

oldagetraveller1 said:

"Where was the lever positioned in your case? Mine is at the top (Auto) position where it has always been."

It was not quite in the "auto position" and would not return to that position. Even when operated manually a couple of times it would only spring back from the "emergency" heating and hot water, lock position to that same place each time. That resulted in the 3 way valve not closing off the heating outlet completely.

BG fitted the new head using some 5? wire plug and socket(ENSTO). That doesn't require accessing the connection box when(not if) it fails again.

 

Your tip seems to have worked. I pushed it down and about 2/3-3/4 it started to resist but I kept pushing and was able to hit the bottom / manual. I then returned it to the Top / Auto and next time it moved freely all the way down and at the moment the HW is on and none of the radiators are warming up. At least that saves my gas bill until BG (Homecare) come out to fix it. I raised a complaint yesterday, they emailed me back saying thank you for your complaint - we have closed it (no further explanation). You cant make it up 

QrizB

nadsat said:

Mister_G said:

The problem with the Honeywell one is that the motor is continuously in the stalled condition.  It only uses a few watts but is powered all of the time.

Surely the power is off when it returns to closed by its spring.

Myu Honeywell three-position valve is "off" at one end (closed by its spring) but the mid position and the other end position are both achieved by stalling the motor.

It's a cheap way of doing it, but not conducive to long life.