New home... ? Plan system issue

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Good morning/evening

Ive just recently moved into a new (old) house and having a problem with the CH & HW...
our system which i suspect is on a W plan is:
  • Glow worm compact boiler - discontinued - no programmer fitted
http://heatingsparesltd.com/downloa...ctions_For_Use_Installation_And_Servicing.pdf

  • 900x450 Immersion heater
  • Honeywell sundial Y plan V4073A1039

The previous owners would use the main switch on the boiler to turn the system off and on as theres no CH programmer to be found in the house which i found bizarre.

Today theres been no HW but the CH has worked fine when the boilers been on so i went to check the immersion heater and the 3 port valve seemed to be stuck halfway, with the little lever moving freely without resistance, when i took the actuator off it would click every second or so and the valve spindle moves freely around 10/15 degrees left and right. Im guessing ill need to replace the actuator as the lever isn't working and its a honeywell model that allows me to without draining. i found the immersion stat under the floor boards which was set to 90 degrees which i imagine is way to high so lowered down to 55.

But heres the wiring, and for some reason im thinking this is wrong and needs redoing... would i be correct? ive also done some research and although the 3 port valve says Y plan i was thinking that i have a W plan so was wondering if you think its worth changing if thats the case?

If anyone could offer help id greatly appreciate it.

Cheers
 
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You can retro fit a timer and thermostat onto the boiler to make life easier.

You'll find the silver Honeywell motor has stopped working or the valve has sludged up most likely.

There is a metal arm on the back of the metal box, dies this have resistance or is it slack?

Also looking at that wiring it would be worthwhile redoing it into a nice wiring centre using correct sleeving where required. If you are going to install thermostats or possibly a smart system of some type it would be wise to do this
 
You can retro fit a timer and thermostat onto the boiler to make life easier.

You'll find the silver Honeywell motor has stopped working or the valve has sludged up most likely.

There is a metal arm on the back of the metal box, dies this have resistance or is it slack?

Also looking at that wiring it would be worthwhile redoing it into a nice wiring centre using correct sleeving where required. If you are going to install thermostats or possibly a smart system of some type it would be wise to do this


Morning mate thanks for the reply!

I had seen that timer option for the boiler I’ll look into that... yeah so the metal arm on the valve moves > > freely with no resistance between auto an man and no ‘whirring’ sound when moving it
> the valve does move when I take the actuator off so I’m hoping it isn’t that!
I think it’s best to do wiring as that seems like a big problem
 
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Also on the valve it’s got
A B
AB

with A I’ve read meant to go to the cylinder for constant hot water however that’s going to the central heating... would this be a problem?
 
No it doesn't matter which way it goes, you can wire the actuator to work either way, just means it's not exactly the same as the drawing.

It's not good practice to do such a thing but it's not end of the world.

When you ask for heating or hot water you should hear the motor move, if you don't then it requires replacement.

I personally recommend not paying the money for the genuine Honeywell one and instead fit the corgi version sold by Toolstation it fits fine and is perfectly adequate in its job and costs a lot less than the Honeywell one
 
No it doesn't matter which way it goes, you can wire the actuator to work either way, just means it's not exactly the same as the drawing.

Don't underestimate the work involved in doing this, it's not just a matter of transposing two wires. The V4073A has a 'hot water off' signal from the programmer and a 'hot water up to temperature' signal from the hot water cylinder thermostat. It's the grey wire in the diagram below.

Capture2.JPG


If the valve were transposed, the grey wire would need to be moved from the hot water side to the central heating controls to provide a 'central heating off' signal from the programmer and and a 'room up to temperature' from the room thermostat, which may require additional wiring to be run [and not all room thermostats have such a connection available]

In addition, when installed normally, the valve sits at rest in the 'hot water only position' and is wound by the motor to the 'heating position' when it gets there, it remains powered but stalled. So normally, during the summer when the central heating wasn't being used the valve would remain unpowered and at rest. If the installation were reversed it would be powered to provide hot water, and a quirk of the valve is that it remains in the last used position even when the programmer turns off. So during the summer when only hot water was being heated the valve would be permanently powered 24/7 consuming power and shortening the life of the motor.


i went to check the immersion heater
Is that what you mean? An immersion heater is an electric heating element that is 'immersed' into the hot water cylinder and is nothing to do with the boiler.

Capture.JPG


found the immersion stat under the floor boards

The immersion heater thermostat is inside the top cover and is an integral part of the immersion heater. If you are referring to a hot water cylinder thermostat that is wired to the motorised valve then that should be strapped to the hot water cylinder about a third of the way up from the bottom where it can sense the temperature of the water inside the hot water cylinder. It shouldn't be under the floorboards

Capture1.JPG
 
Last edited:
Don't underestimate the work involved in doing this, it's not just a matter of transposing two wires. The V4073A has a 'hot water satisfied' signal from the programmer 'hot water off' and 'hot water up to temperature' signal from the hot water cylinder thermostat. It's the grey wire in the diagram below.

View attachment 252887

If the valve were transposed, the grey wire would need to be moved from the hot water side to the central heating controls to provide a 'central heating satisfied' signal from the programmer 'central heating off' and 'room up to temperature' from the room thermostat, which may require additional wiring to be run [and not all room thermostats have such a connection available]

In addition, when installed normally, the valve sits at rest in the 'hot water only position' and is wound by the motor to the 'heating position' when it gets there, it remains powered but stalled. So normally, during the summer when the central heating wasn't being used the valve would remain unpowered and at rest. If the installation were reversed it would be powered to provide hot water, and a quirk of the valve is that it remains in the last used position even when the programmer turns off. So during the summer when only hot water was being heated the valve would be permanently powered 24/7 consuming power and shortening the life of the motor.



Is that what you mean? An immersion heater is an electric heating element that is 'immersed' into the hot water cylinder and is nothing to do with the boiler.

View attachment 252884



The immersion heater thermostat is inside the top cover and is an integral part of the immersion heater. If you are referring to a hot water cylinder thermostat that is wired to the motorised valve then that should be strapped to the hot water cylinder about a third of the way up from the bottom where it can sense the temperature of the water inside the hot water cylinder. It shouldn't be under the floorboards

View attachment 252885

I'm not suggesting it is, but the op has stated his has been fitted in reverse.

Mine at home has also been fitted in reverse for whatever reason but works fine.

I was merely commenting that it's not unusual for it to be fitted incorrectly compared to the diagram and that it is nothing to worry about.
 
I can't see that I disagreed with you did I? Just thought the OP might find it useful to know that there was more involved in swapping it over than just exchanging 2 control wires at the valve, and that it would shorten its life.

However, I did read the post in reverse and thought it was currently wired correctly as per the diagram and he had wanted to transpose it for some reason. However the work involved to change it back to the normal convention would be the same.
 
Don't underestimate the work involved in doing this, it's not just a matter of transposing two wires. The V4073A has a 'hot water off' signal from the programmer and a 'hot water up to temperature' signal from the hot water cylinder thermostat. It's the grey wire in the diagram below.

View attachment 252887

If the valve were transposed, the grey wire would need to be moved from the hot water side to the central heating controls to provide a 'central heating off' signal from the programmer and and a 'room up to temperature' from the room thermostat, which may require additional wiring to be run [and not all room thermostats have such a connection available]

In addition, when installed normally, the valve sits at rest in the 'hot water only position' and is wound by the motor to the 'heating position' when it gets there, it remains powered but stalled. So normally, during the summer when the central heating wasn't being used the valve would remain unpowered and at rest. If the installation were reversed it would be powered to provide hot water, and a quirk of the valve is that it remains in the last used position even when the programmer turns off. So during the summer when only hot water was being heated the valve would be permanently powered 24/7 consuming power and shortening the life of the motor.



Is that what you mean? An immersion heater is an electric heating element that is 'immersed' into the hot water cylinder and is nothing to do with the boiler.

View attachment 252884



The immersion heater thermostat is inside the top cover and is an integral part of the immersion heater. If you are referring to a hot water cylinder thermostat that is wired to the motorised valve then that should be strapped to the hot water cylinder about a third of the way up from the bottom where it can sense the temperature of the water inside the hot water cylinder. It shouldn't be under the floorboards

View attachment 252885

thankyou for the reply... looking at how everything is wired it’s just a rats nest and doesn’t really look like it’s been done properly, there’s usually a 10 at j.b isn’t there but this has somehow fitted into a 3 way one.

The immersion heater, I used mistakenly as a general term, so I went to check the 3 port valve which is by the cylinder and come across the stat under the floor boards turned to 90 oC but I’m used to seeing them as you described attached to the cylinder.

so if I was to get the replacement motor would that suffice for now until I can get the wiring checked properly?... we’re planning on getting a combi installed in the new year anyway to I’m just looking for a way to get us through till then
 
I would say it seems the motorised valve is OK and some wiring fault, but I got caught out with a Y Plan, the W Plan heats up DHW first, and when hot does central heating, the Y Plan can do CH and DHW at the same time.

The Y plan valve is complex, with micro switches and diodes inside, so can give some odd results when testing.

mid-position-valve.jpg
 
I would say it seems the motorised valve is OK and some wiring fault, but I got caught out with a Y Plan, the W Plan heats up DHW first, and when hot does central heating, the Y Plan can do CH and DHW at the same time.

The Y plan valve is complex, with micro switches and diodes inside, so can give some odd results when testing.

View attachment 252901
Hi Eric,

Thankyou for your response.. so you would say our actuator is fine or would you say it’s better to replace the motor just to be safe? Or get the wiring done properly first and see if that solves any problems?

cheers
 
Also on the valve it’s got
A B
AB

with A I’ve read meant to go to the cylinder for constant hot water however that’s going to the central heating... would this be a problem?
well you have read wrong, B is for HW goes to the cylinder and A is for radiators, and it doesnt matter what you set the cylinder stat to if it is under the floorboards
 
so if I was to get the replacement motor would that suffice for now until I can get the wiring checked properly?... we’re planning on getting a combi installed in the new year anyway to I’m just looking for a way to get us through till then
Just remove the actuator head and leave it off, manually set the valve to mid position and control from the boiler and you will have CH and HW till your new boiler is installed
 

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