Honeywell v4073a1039 motorised 3 port valve: should moving lever to manual allow flow?

Your pump is not a pump, it is a circulator. You cannot establish flow through a radiator through the bleed screws. You will get water from the bleed screws if you have a positive head (pressure) to the circuit. It is this pressure that allows the pump to circulate water. If you get nothing from the radiators, then you have no 'head' so therefore no flow. Bite the bullet and get in someone who can find and rectify your faults.
 
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Are you saying that there is no difference between
1) Opening a bleed screw with the pump active
2) Opening a bleed screw with the pump off

Because if you are, I think you are wrong. I have done this on an upstairs radiator when my pump was working some years ago and there was a big difference in the behaviour, in fact I think water was sucked out of the radiator.

The fault procedure in the boiler manual doesn't cover the issues I have had.

I will replace my dubious pump with my old pump and see if that changes the behaviour of the system.
 
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You have received lots of constructive advice from several professionals who are trying to help you. You've managed to question/disagree with most of this. Is it any wonder that we lose patience?
 
The only thing I have questioned is your claim that bleeding radiators with the pump on or off makes no difference.

To claim anything else is simply erroneous.

You have not offered any answers to many of my questions such as
1) What does the grundfos pump offer that the dabs doesn't
2) What is the behaviour of a functioning honeywell valve with regard to the lever when put in a manual position
3) How can a pump with a rotating spindle not be pumping
4) and others

I appreciate you have taken umbrage, the only advice you have offered, except for one useful post at the start is "to get a man in", are you aware of the name of this forum?

Well anyway, I have removed the pump and I don't seem to be getting any water feed to the inlet of the pump, even with the isolation valves open.

boiler%20system3.png


Looks like I may have to get a "man in". The device for indicating the presence of water has not been indicating this for some months, so perhaps my problem is more serious than just a pump or valve problem.
 
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That was the conclusion I initially came to, but then I realised that required that there is a constant loss of water in the system when the heating is used intensively that has to be made up with the feed. Perhaps that is a reasonable assumption.

Is there a good way to clear it such a pipe?

I do have a bendy wire thing for clearing pipes, would that be a good thing to try?

I did have an incident with the expansion tank some months ago when the ballcock stuck and the water level became low, perhaps something went down the feed?
 
I was a little reluctant to come to that conclusion as that would only occur if there is a constant loss of water in the system when the heating is used intensively. Perhaps that is a reasonable assumption

The problem with assumptions.

Is there a good way to clear it?

Cut it out and replace it.
 
Well I can do that. I even have pipe benders and the like.

Hhhhhhhhhmmm.......... and the amount of copper tubing required is quite small and I can join onto the existing pipe work with a simple joint.

It doesn't seem like there can be any other explanation for the lack of water.

And of course this would account for my pump running and there being no flow, it was running on air, and I thought the poor valve was at fault.

This would also explain why the problems have occurred when the heating was running more intensively and there was greater water loss.

Is it worth trying to stick my bendy wiry pipe cleaner down it first? Or is that just a waste of time?
 
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WOW!!!!!!!!!!!!!!!!!

Those are some scary pictures!!!!!!!!!

Are they of feed pipes or just pipes in general?
 
The pipes near the pump are not clogged up, but then that is new pipework put in 8 years ago, I don't think the rest of the central heating can be like that because it was all working fine a week or so ago or at least it would work when I bashed the area around the pump for a bit.
 
Dan, anyway, thank you so very much for that suggestion, I do believe that is what I will do!

I suppose if I cut the feed and find that it isn't horribly blocked I can always join the old pipes together.
 

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