Honeywell 3-way valve defective?

Joined
2 Aug 2016
Messages
26
Reaction score
0
Country
United Kingdom
V4073 A1039.

There is power to the CH/HW controller (a Horstmann Centaur Plus c27) but both CH and HW are off (no red lights on controller unit).

HOWEVER, the head unit of the 3 way valve is quite warm..none of the pipes connected to the valve are because nothing (CH/HW) has been "on".

I put CH on to "24hrs" just now and the boiler fires fine and heat gets to rads. I then switched CH back to OFF.

I then tried HW only on "24hrs" but nothing happens at the boiler? HoI wever..currently have a cylinder full of hot water courtesy of the immersion?..would that stop the boiler firing up when on HW only?..possibly I'd have thought?

From memory when I last had it on HW only water (i.e. CH is "OFF")..I got hot water coming into the rads. I will try the HW only setting again in the morning when the HW cylinder has cooled off/emptied of hot water and report back here.

Just concerned really that the head unit is quite warm..(not hot though) as described as above when the boiler has not been used in days.
 
Last edited:
Sponsored Links
There are two requirements to get CH.
First the valve has to driven to the correct position and secondly power has to be supplied through the room stat is and valve head to light boiler.
When room stat is satisfied power to light boiler is cut, but valve position remains.
This means the motor is still energised waiting for room stat to supply power again.
If heating is turned off last thing at night, the motor is energised throughout the night and the valve head will be quite warm
 
many thanks for that lucid explanation Mandate. This particular house is a second home that we only use for 4 months or so a year..usually in the (UK) Summer..and the "warm" valve-head has been like that for 12 months (or longer..because before I had not noticed it to be warm)

..so it seems quite normal that it gets warm.

As I say I am fairly sure that one time a year or so back I fired up HW only and there was "leakage" to the rads.. so I just used the immersion instead as I was in a relative hurry.. and I never got round to returning to "the job".

I was going to replace the whole thing (as I did some 10 years ago).. but if it is normal for the head-unit to be warm, because it's energised as you suggest, I won't bother right now. It was a safety issue in my head rather than owt else..and you have I think set my mind at rest.

once again many thanks for explaining the source of the "warmth".

p.s what would cause leakage to the rads (i.e CH).. if the "controller" was set as HW only? (CH off)
 
You can prevent the head being warm if you select HW which will allow valve to return to HW position and then switch off.. Motor no longer energised..
If rads get warm with only HW then valve must be sticky and not fully returning to the rest position (HW)
 
Sponsored Links
It is good for the system to be exercised once ever few weeks by selecting HW only for a couple of minutes and then CH only for a couple of minutes.

That ensures the valve and system pump do not seize up.

Tony
 
many thanks for that lucid explanation Mandate. This particular house is a second home that we only use for 4 months or so a year..usually in the (UK) Summer..and the "warm" valve-head has been like that for 12 months (or longer..because before I had not noticed it to be warm)

..so it seems quite normal that it gets warm.

As I say I am fairly sure that one time a year or so back I fired up HW only and there was "leakage" to the rads.. so I just used the immersion instead as I was in a relative hurry.. and I never got round to returning to "the job".

I was going to replace the whole thing (as I did some 10 years ago).. but if it is normal for the head-unit to be warm, because it's energised as you suggest, I won't bother right now. It was a safety issue in my head rather than owt else..and you have I think set my mind at rest.

once again many thanks for explaining the source of the "warmth".

p.s what would cause leakage to the rads (i.e CH).. if the "controller" was set as HW only? (CH off)
 
don't know why my first reply from yesterday evening was just replicated?..clicked reply & was just going to say thanks to the two extra posts (Mandate & Tony..one lives and learns).
>Mandate, you say "valve must be sticky and not fully returning to the rest position (HW)" I see, and I am sure you are correct. Please can you (or anyone else who feels like helping me) give me a tip as to how to free it up.
 
Usually frees itself when its used a bit.
 
will do what you say..we rarely use boiler from June to Mid Sept. so quite likely just a bit of exercise needed. Anything more I could do if usage doesn't fix the "leak" of HW to CH.
 
@ ron56

Out of curiosity, could you check that the small lever on the 3 port valve head is actually set in the auto position and not in the manual position which, if it was, would contribute towards the symptoms described.

regards
 
Most of those valves will not stay in the manual position if the motor is working and each function has been selected.

The manual position puts the valve in the mid position for flushing and testing.

I presume they are designed to return to auto to prevent them being accidentally left on manual.
 
The problem may be more related to the gear teeth on the motor and quadrant.
Constant use causes burrs to be formed at the edges and may cause fouling.
Also you can lift the head off the spindle and test to see if valve turns easily using finger and thumb.
If stiff try silicone lubricant
 
thanks again all, very kind. well I read Mr. Therms post and having crawled under the HW cylinder in the airing cupboard I find the lever is on manual. Mmm -so I move it back to auto..but its all a bit "floppy". I turned off the power to the 3-way and Horstman programmer..switched on again and definitely some vibration felt with palm on the valve head.
I set the programmer to CH only (24hrs)..on comes (oil) boiler..rads start to get warm (this .as never been a problem..the heating part is left on in 24/7 over Winter if we're not around on the insurers recommended level using the room-stat..well maybe 8C not 10C). I switch CH to off and set HW to 24 hrs continuous..a cold HW cylinder right now so the boiler comes on..and after about 10 minutes there is only hot water going to the rads side of the 3-way..but nothing or very little to the HW cylinder!

When I push gently on the lever to move it to Manual..there is no resistance from the spring at any point in its travel to the Manual end of the slot. I think I shall probably have to buy a whole new valve and drain the system down.

IF I decide to leave the job until early next Summer I guess it's safe?..as explained by Mandate the residual warmth I could always feel at the valve head just being the result of the 5 watts or whatever it sups to keep it in the energised state that it needs to be when the programmer is
permanently on CH only (24hrs)?

Any further advice will be gratefully received.

p.s. Mandate by silicone lubricant..for e.g. GT85? (I have some)..or WD40 (is that silicon) EDIT JUST READ NOT TO USE WD40)..also have silicone grease in my car box.
 
Last edited:
The shaft has two "O" ring seals and external lubricant will help the outer one but not get past it to the inner one.

It is possible to buy a repair kit with a new bearing plate and sealing ball. They only take a few minutes to fit once the system is drained.

But generally they will free up with a little use or by manually twisting many times using an adjustable spanner but better not to spoil it with pliars.

It seems that yours was not unlatching from the manual position as it should when selected to CH only. But that is not important as long as you do not leave it there. That may well have been why you were heating the rads when you only wanted water.
 
Last edited:

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top