honeywell 4073 diverter valve. Ist this right.

[kipperlynch]

possibly not a problem but wanted to know how much travel the manual arm on the valve should travel as my one seems to only travel from half way up the opening and when i operate the lever it seems to remain at the top until i turn off the electricity to the system and then it returns to the half way mark.

I wanted to know because some of the rads are warming up when the CH room thermostat has been turned down to well below the surrounding temp.

 

[giblets]

It sounds like you may be getting "let-by" on the three-port valve. This can either be caused by wear in the rubber ball inside the valve or a build-up of deposits on the seatings, again, inside the valve. To check, if you let the system cool down and then turn on the hot water circuit only feel the outlet from the valve to the radiators. If it gets hot you are getting let-by. Either a service or replacement will cure the problem.

BTW if you have Fernox inhibitor in the system this has been known to cause the rubber ball in the valve to swell and not seat correctly.

 

[DavidJW]

wanted to know how much travel the manual arm on the valve should travel as my one seems to only travel from half way up the opening.

The manual arm is no indication of the position of the valve. When the valve is in one direction the lever is right over (you can't move it easily), but when the valve is over to the other side, the lever can be moved about quite easily. The sole purpose of the lever is to be able to hold the valve open against the return spring while filling the central heating.

One cause of rads heating up when they shouldn't is reverse flow. In other words hot water is flowing along the return pipe to the rad. This is usually caused by the main flow and return pipes not plumbed in correctly. Search the forum for "reverse flow"

 

[Softus]

BTW if you have Fernox inhibitor in the system this has been known to cause the rubber ball in the valve to swell and not seat correctly.

That's news to me. Do you have any more information about this?

 

[giblets]

BTW if you have Fernox inhibitor in the system this has been known to cause the rubber ball in the valve to swell and not seat correctly.

That's news to me. Do you have any more information about this?

Information received from an ex-Honeywell employee and also from personal experience in replacing over 15 balls in systems where Fernox has been used. Never had any probs at all with Sentinel treated systems.

 

[Softus]

Interesting.

I must ask Fernox...

 

[giblets]

Interesting.

I must ask Fernox...

I would be keen to hear their comments.

 

[Softus]

I'll let you know, but I got the distinct impression that you'd already made you mind up.

 

[giblets]

I'll let you know, but I got the distinct impression that you'd already made you mind up.

Only based on actual experience. Might be worth a word with Honeywell to.

 

[Softus]

So are you saying that what you've experienced might be down to coincidence, and that the balls might have failed for some other reason? Perhaps not enough Fernox to correct the pH of the CH water?

 

[pannierstan]

So are you saying that what you've experienced might be down to coincidence, and that the balls might have failed for some other reason? Perhaps not enough Fernox to correct the pH of the CH water?

No I can assure you Softus that it is indeed the chemicals as Giblets has mentioned and usually when alot of them .
I also have changed more Ball plates than I care to mention on Honeywell valves due to balls swelling.
My experience was never conclusive but certainly Fernox seemed to be the main culprit.
Thing is sludge will often make a valve pass but a swollen ball will usually just inhibit flow or make the valve clang when crossing ports.
If you really know what you are doing the manual lever can be an indication as the lever will not actually fall right back to the end of its travel. If the heads removable then thats another way by checking the movement on the spindle itself.

To the original OP . The manual arm will do exactly what you describe unless you turn the power to the system off as you are pushing the valve past the mid postition at which point it will wind fully to heating position anyway hence you will loose any sring on the lever However it sounds like the valve is passing slightly.

Stan

 

[Softus]

No I can assure you Softus that it is indeed the chemicals as Giblets has mentioned.

Somehow I don't feel very assured, and I still feel a need to understand why it happens.

I also have changed more Ball plates than I care to mention on Honeywell valves due to balls swelling.
My experience was never conclusive but certainly Fernox seemed to be the main culprit.

Again, what evidence is there that too much Fernox, as opposed to too little, was the cause?

 

[pannierstan]

Good god man maybe its easier for me to just say the ball was swollen so I changed it!

Alas I havent had time in the last 30 years to look into why it happens only that there was a whiff of fernox about and probably an empty MB1 bottle in the loft but hey whatever floats yer boat if you want to work out the chemical constitution of each and then ascertain the exact cause was actually flux debris or the fact that the system was filled with Evian go for it.

Stan

 

[Softus]

Good god man maybe its easier for me to just say the ball was swollen so I changed it!

You seem to be irritated by the fact that I have an enquiring mind. Good luck with that.

Alas I havent had time in the last 30 years to look into why it happens...

And yet you have enough time to take the p*ss out of someone who wants to look into it.

 

[pannierstan]

Not really irritated Softus. I just presumed that to have a reply from someone else who has experienced the same problems as Giblets MIGHT satisfy your curiosity on the subject.
However if you are questioning the findings then say so. If you have a better suggestion as to why the rubber swelled then please do inform us all.