No flow through rads

[ianmcd]

I asked a specific question about 3pvs. Have you got anything to contribute or are you just intentionally wasting bandwidth?

(Why is that everytime someone posts something on this forum it starts an inquisition? It's only a central heating system, not quantum physics.)

Your know-it-all attitude and arrogance are astounding considering you have come to the forum for advice. Concerning a heating system YOU can't seem to diagnose or fix. Without help.

And you won't be receiving any more of mine, you obnoxious little man.....

Bolshy I feel that your comments to the OP are not really constructive but completely up to you how you respond to any comment on here, but please leave it to us to sort out the OPs problem as it is so easy for a post on here to get Hi-Jacked with people slagging each other off , cheers for your input

 

[bolshy]

Have you got anything to contribute or are you just intentionally wasting bandwidth?

It's only a central heating system, not quantum physics.

Well, if he wants help he shouldn't be insulting people. And from his posts, he clearly believes he is too intelligent for the likes of some of those who were offering help. Like Tony.
So my statement stands.
And if anyone's trolling, it's the OP.
End of transmission.

 

[david3456]

Bolshy I feel that your comments to the OP are not really constructive but completely up to you how you respond to any comment on here, but please leave it to us to sort out the OPs problem as it is so easy for a post on here to get Hi-Jacked with people slagging each other off , cheers for your input

Thank you, my son in law has continued to work on it alone today. We have reached the conclusion that a gate valve on the rad side of the 3pv could be stuck shut despite the shaft appearing to turn properly. (Not in circuit when we flushed) It was too late this afternoon to strip down again to check since it was worth keeping the system going, such as it is.

You may be interested in the boiler plot I made yesterday https://docs.google.com/file/d/0B4xffi9ItIebNnptemRmdzgxa2c/edit?usp=sharing

This was recommissioning after the flush (red flow, blue return, yellow difference). It starts with high bypass before we homed in on the hw setting to get a reasonable ~10 degree difference. About 2/3 of the way through shows a couple of unsuccessful attempts at switching to rads without bypass.

Clearly, when switching to rads the 3pv is fully closing the hw side. Yet the rad side is somehow not being released.

 

[D_Hailsham]

A TRV shuts down a radiator when the room has reached the temperature that the user has set on the TRV.

But a TRV is not a switch. It is a flow control device which adjusts the flow through the radiator so the heat emitted by the radiator is just sufficient to maintain the required room temperature. If a TRV is acting like a switch, so the radiator is alternately hot then cold, it normally means that the system has not been balanced correctly.

Most TRVs are designed to be fully open if the ROOM temperature is more than 1°C below the set temperature, and fully closed when the ROOM temperature is more than 1°C above the set temperature.

 

[Agile]

Clearly, when switching to rads the 3pv is fully closing the hw side. Yet the rad side is somehow not being released.

If you looked inside a valve you would see that they cannot do that because the rubber ball cannot be in two places at once!

Tony

 

[david3456]

Clearly, when switching to rads the 3pv is fully closing the hw side. Yet the rad side is somehow not being released.

If you looked inside a valve you would see that they cannot do that because the rubber ball cannot be in two places at once!
Tony

Yes, that was one of the questions in my first message. I know it should not be possible but is it totally, absolutely impossible? You agree that my boiler plot shows the valve is not stuck in one position?

Though by "rad side" above I intended to mean the rad circuit in general (which might include the 3pv) not the exit of the 3pv specifically.

 

[doitall]

Would love to see some information about the system, with a few makes and models and type of system.

Blocked return or pump is in the lead so far.

 

[Agile]

Thank you, my son in law has continued to work on it alone today. We have reached the conclusion that a gate valve on the rad side of the 3pv could be stuck shut despite the shaft appearing to turn properly. (Not in circuit when we flushed) It was too late this afternoon to strip down again to check since it was worth keeping the system going, such as it is.

Has that gate valve been visually checked inside?

Tony

 

[CBF]

why have you got a gate valve on your heating circuit anyway

 

[david3456]

Thank you, my son in law has continued to work on it alone today. We have reached the conclusion that a gate valve on the rad side of the 3pv could be stuck shut despite the shaft appearing to turn properly. (Not in circuit when we flushed) It was too late this afternoon to strip down again to check since it was worth keeping the system going, such as it is.

Has that gate valve been visually checked inside?

No, we were too occupied in improving the basic boiler operation to imagine a gate was also faulty. Something for next weekend. I will let you know the result. Apart from that, there doesn't seem to be any need to continue this thread.

 

[CBF]

Apart from that, there doesn't seem to be any need to continue this thread.

very true i'm not even sure why you came on here & asked in the first place as you seem to know everything

 

[david3456]

Apart from that, there doesn't seem to be any need to continue this thread.

very true i'm not even sure why you came on here & asked in the first place as you seem to know everything

Thank you for your input. It would help matters considerably if people replying actually answered an OP's questions rather than spending time questioning their parentage and trying to offer advice.