Almost without a doubt, the Honeywell actuator has begun to jam/stick. I would though like someone to be able to confirm the actual valve spindle is only intended to rotate that 20 deg you mentioned earlier.
Boiler not switching on, pump not running, no hot water - please help?
- Thread starter HazelFlorist
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Almost without a doubt, the Honeywell actuator has begun to jam/stick. I would though like someone to be able to confirm the actual valve spindle is only intended to rotate that 20 deg you mentioned earlier.
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Indeed.
On reflection, it was probably more like 30-40 degrees, but no more, with the spindle hitting a definitive and solid 'stop' at the end of each travel, met with a fluid 'thunk' as flow stopped or opened, leaving me to feel this was 'correct'??
That is correct for that valve
Thanks Ian, so it does just need a new head / actuator.
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I would tell you but according to you I "However, lacks the professionalism to enter a discussion without being offensive to other forum members."
Read more: https://www.diynot.com/diy/threads/converting-to-combi-pipework.527086/page-2#ixzz5wIYvAJzS "
so guess what ?
I gave you the benefit of the doubt this time.
For the original poster, as Ian seems not to be willing to help, just buy yourself a new actuator head, the actual water valve would seem to be OK. Screwfix offer the actuator separately from the valve - https://www.screwfix.com/p/honeywel...acement-powerhead-22mm-22mm-compression/273fv £84.
Lots on ebay, much cheaper - https://www.ebay.co.uk/sch/i.html?_....TRC0.A0.H0.Xv4073a.TRS0&_nkw=v4073a&_sacat=0 as low as £35 for the complete unit.
Links in this post may contain affiliate links for which DIYnot may be compensated.
And if it turned 360 deg it would be back in the exact same position that it started in, take a wild guess at why a Mid position valve is called just that
HazelFlorist, there is something you describe that that would not be caused by a faulty motorised valve:
Therefore, the boiler is not firing up when the hot water is set to be 'on' at the programmer and the cylinder thermostat is calling for heat. If you have a look at the basic wiring diagram I've posted below, you will see that the sequence of control of the hot water is:
Programmer switches hot water 'on', and is wired directly to the------>Cylinder Thermostat which also when 'on' is wired directly to the boiler ----------> Boiler switches 'on'
If you follow the circuit through, you will see that there is no electrical connection whatsoever via the motorised valve. So whatever position the motorised valve was in, the boiler would still fire up when the hot water was calling for heat. (and you tell us that it isn't)
If the valve was sticking in the 'heating only' position, the boiler would still heat up when the hot water was on, but the hot water would flow to the radiators instead of the hot water.
Therefore, the boiler is not firing up when the hot water is set to be 'on' at the programmer and the cylinder thermostat is calling for heat. If you have a look at the basic wiring diagram I've posted below, you will see that the sequence of control of the hot water is:
Programmer switches hot water 'on', and is wired directly to the------>Cylinder Thermostat which also when 'on' is wired directly to the boiler ----------> Boiler switches 'on'
If you follow the circuit through, you will see that there is no electrical connection whatsoever via the motorised valve. So whatever position the motorised valve was in, the boiler would still fire up when the hot water was calling for heat. (and you tell us that it isn't)
If the valve was sticking in the 'heating only' position, the boiler would still heat up when the hot water was on, but the hot water would flow to the radiators instead of the hot water.
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I think you might be right..... if stopped working again.
I pulled the motorised head off the valve, messed about with it, moved the switch from auto to manual and back as I did last time (this time it was not loose) and nothing made the pump come on - no amount of fiddling did anything.
I messed with the tank stat a little then gave up as I had to go out.
I came back later and started to mess with it again and suddenly it;s working again - most frustrating.
It was interesting that though that actioning the micro-switch in the valve head this time did not make the pump come on.
Your wiring diagram and operational protocol makes sense and leads me to think it is indeed something else, as logic insists that irrespective of the valve, the pump and boiler should fire.....
.... therefore, and forgive my electronic ignorance, but could it be a faulty cylinder stat?
It's the original stat that was on the cylinder when the house was built in 1989 so is now 30 years old. Could it adopt a status that would stop it sending a signal to the boiler to fire up?
Before you mess and fiddle to the point you create more problems than you're trying to solve, I would strongly recommend you get someone in who has progressed beyond the messing and fiddling stage of plumbing and heating fault diagnosis and repair.
Now you are being silly. Some 3 port valves can be freely turned through the entire 360 degrees of freedom, yes 360 degrees would be the same position it started. Actuators only drive them back and forth through a limited range.
My own 3 port valve actually operates through the entire 360 degrees, to set the open port - it only rotates in one direction of rotation. Have you ever heard of MOMO?
Ian, with all due respect - there is a person here seeking some help to solve a problem with his heating system. Your contributions seem intent on picking the bones out of my own attempts to help him. Have you really got so little to occupy your time?
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"MID" PORT!
The stat is just a simple switch, which is operated by temperature. As you sweep its setting knob across its range of settings, it should click on the way up and on the way down, at around the same setting, depending on the cylinder's temperature. The clicking doesn't guarantee it is working properly, but it would suggest it is. Likewise your room stat, should click as well, if its an old fashioned mechanical one.
Most likely point of failure, remains that 3-port valve actuator head.
I can only apologise for the poor signal to noise currently in this thread..
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Equally often called a 3-port.
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Thanks for your input.
Still not working, and I cant afford a plumber/electrician at the moment so I'm having to muddle through as best as I can.
The comment earlier about the 3 port being a red herring and that the cyl thermostat being a key element interests me and stimulates my logic, so I pulled the cover off the electrical box in the airing cupboard and traced the 3 wires from the cyl stat into the choco-bloc connector. Trying not to electrocute myself, I came to the (hopefully not deadly) conclusion that with the cyl stat turned fully cold and then fully hot, in those two positions there should be 240V across two of those three wires, so I tested for that and got nothing from any two wire combos with the stat in any position - all this with the timer set to 'hot water'.
Does that tell us anything?
I'd have expected to measure some voltage there surely?
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