You can open up the valves on the furthest or coldest radiators fully if you want. The important piece of information is that between about 2 turns and 7 turns very little happens. Then the last couple of turns will quite rapidly shut down the flow.
Central Heating Balancing query
- Thread starter Longclough
- Start date
Sponsored Links
To provide an update:
I have the bypass gate valve, so that it open about 1/4 turn. By feel the pipe is still warm on the return side of the gate valve.
My only concern is when the pump is in overrun, therefore both motorised valves closed the pump seems a later louder like it is struggling to pump. Is this normal?
Would fitting an auto bypass be a good idea?
2 only other thing of note:
when the pump came back on, there was a gushing water (Like boiling or air) for about 5 seconds. any ideas? it only happened once
The boiler seems to cycle a little bit more often now?
I have the bypass gate valve, so that it open about 1/4 turn. By feel the pipe is still warm on the return side of the gate valve.
My only concern is when the pump is in overrun, therefore both motorised valves closed the pump seems a later louder like it is struggling to pump. Is this normal?
Would fitting an auto bypass be a good idea?
2 only other thing of note:
when the pump came back on, there was a gushing water (Like boiling or air) for about 5 seconds. any ideas? it only happened once
The boiler seems to cycle a little bit more often now?
That's bound to happen when the gate valve is open, even a 1/4 turn, as there will always be a flow through it.
Its caused by the restriction of having the gate valve open only a 1/4 turn. Opening the gate valve more would help, but that would reduce the flow through the radiators.
Yes. It's the approved method nowadays as it only opens when necessary and the amount it opens varies with conditions.
Opening the gate valve another 1/4 turn may help, but the correct solution is an ABV.
D_Hailsham, thanks again for your advice. I took your advice and open the bypass another 1/4 turn and on pump overrun, the pump runs fine now.
This morning I confirmed that all the radiators get really hot when both CH and HW are ON.
I am still concerned about the bubbling sound in the pipework just after the pump, as I could also hear it in the first radiator as well (I have to admit that I could hear in the pipework from time to time, before I made changes). What is this likely to be?
Could it be that the pump, although set to 2 needs reducing to 1. I also tried to bleed the pump and upstairs radiators when the system had cooled down, but only water came out of them.
This morning I confirmed that all the radiators get really hot when both CH and HW are ON.
I am still concerned about the bubbling sound in the pipework just after the pump, as I could also hear it in the first radiator as well (I have to admit that I could hear in the pipework from time to time, before I made changes). What is this likely to be?
Could it be that the pump, although set to 2 needs reducing to 1. I also tried to bleed the pump and upstairs radiators when the system had cooled down, but only water came out of them.
Sponsored Links
Air could be getting sucked into the system via the vent pipe - thats the one which hangs over the top of the small tank in the roof. Here's how you check:
Turn the system off
Fill a container with water
Go up in the loft
Hold the container so the end of the vent pipe is in the water.
Turn system on.
If the water gets sucked out of the container, air is entering the system via the vent.
You may be able to stop this by slowing the pump down, but that could mean you don't get proper circulation through the radiators. It's worth a try as it's the easiest option.
D_Hailsham, Thanks again
I checked and there is no vent pipe on our CH system.
The F/E tank only has 3 pipe. Cold feed, Overflow and pipe in bottom which I assume is for feeding and expanding.
I did notice that some of the radaitor LS appear to be on the flow side. Could this cause air to be generated during circulation
I checked and there is no vent pipe on our CH system.
The F/E tank only has 3 pipe. Cold feed, Overflow and pipe in bottom which I assume is for feeding and expanding.
I did notice that some of the radaitor LS appear to be on the flow side. Could this cause air to be generated during circulation
That's OK. You have a "combined feed and vent" system. The pipe at the bottom should be 22mm.
It does not matter which side the LS valve is; all it does is control the maximum flow through the radiator.
Do you still get the bubbling sound round the pump? If so when does it occur?
What is the vertical distance between the water level in the F&E tank and the pump?
Can you post a pic of the pump and all the surrounding pipework (One pic will do)?
There is a picture on page 1, does it show what you require?
The bubbling in the pipework in the region of the pump and then in the 1st radiator immediately after the pump. it occurs when the boiler fires up. I opened up the LS on that radiator a bit and it is less noticeable!
It also becomes less noticeable if I open up the bypass gate valve by 2 turns or so!
The bubbling in the pipework in the region of the pump and then in the 1st radiator immediately after the pump. it occurs when the boiler fires up. I opened up the LS on that radiator a bit and it is less noticeable!
It also becomes less noticeable if I open up the bypass gate valve by 2 turns or so!
Yes.
Can you please identify the five pipes going out of the top of the pic?
What is the device at the top of the very left pipe?
The joints seem to have leaked slightly as there is a deposit on many of them.
The pipe to the right of the pump is obviously the bypass, but what is the thing on the top of the bit sticking up and going nowhere?
You forgot to answer this question: What is the vertical distance between the water level in the F&E tank and the pump?
To answer your question I missed, I would say that the height is approx 1.8 - 2m.
I can see your issue with identifying the pipes as I am struggling just looking at the picture in work. I will have a go.
The 3 pipes from the pump from left to right are:
1) CH - radiator flow
2) HW - cylinder flow
3) bypass pipe. (Thing on top I think is a venting point, but have no idea really)
The 3 pipes attached to the wall directly behind the pump from left to right.
1) Hot water from cylinder (Lagged pipe)
2) Mains cold water, which T's and goes to feed Cylinder and F/E in loft
3) F/E pipe which is connected to boiler flow pipe (before the pump I think)
The other two pipes are for the unvented cylinder, the balck thing is the tundish I believe!
Hope this is helpful info!
I can see your issue with identifying the pipes as I am struggling just looking at the picture in work. I will have a go.
The 3 pipes from the pump from left to right are:
1) CH - radiator flow
2) HW - cylinder flow
3) bypass pipe. (Thing on top I think is a venting point, but have no idea really)
The 3 pipes attached to the wall directly behind the pump from left to right.
1) Hot water from cylinder (Lagged pipe)
2) Mains cold water, which T's and goes to feed Cylinder and F/E in loft
3) F/E pipe which is connected to boiler flow pipe (before the pump I think)
The other two pipes are for the unvented cylinder, the balck thing is the tundish I believe!
Hope this is helpful info!
Sorry you say that the pipes look like they have leaked.
Having assessed the pipework, I have not noticed any leaking I thought the mess on the pipes was where solder had been dripped on the pipework
Having assessed the pipework, I have not noticed any leaking I thought the mess on the pipes was where solder had been dripped on the pipework
That's OK; it's more than the minimum required by the pump manufacturer.
Thanks for the pipe info.
Thought it might be. Is there a makers name? Is there a screw or nut on the top which can be undone? I just wonder if air is collecting there.
As for the leaking pipes, it was just that there appeared to be a lot of green deposits which is typical of the effect of water on copper. But if your satisfied that all the joints are sound, that's OK.
D_Hailsham,
Thanks for all your info.
I too wondered if it was too if air could be collecting there.
It is a screw on top, I was going to post in a separate post cause I have tried to open it to vent out air, but have been unable to get it open!
That is in the region of where the bubbling sound starts. Ultimately I will try and fit an Auto-bypass and try and balance the system more in the summer.
So far the improvements I have made allow for all radiators to get warm, with Pump set to 3. They all get warm with both HW/CH set to ON with pump set to 3 (Although not as warm as with just CH). Bypass is open 1/2 a turn and seems to function correctly.
System seems fine in so much as yesterday CH was turned on at 14 ish, by 3 house was at 17.5 degrees and up till 10 when CH went off, the boiler cycled for about 10 mins every 45 mins or so. I am happy with that!
Thanks for all your info.
I too wondered if it was too if air could be collecting there.
It is a screw on top, I was going to post in a separate post cause I have tried to open it to vent out air, but have been unable to get it open!
That is in the region of where the bubbling sound starts. Ultimately I will try and fit an Auto-bypass and try and balance the system more in the summer.
So far the improvements I have made allow for all radiators to get warm, with Pump set to 3. They all get warm with both HW/CH set to ON with pump set to 3 (Although not as warm as with just CH). Bypass is open 1/2 a turn and seems to function correctly.
System seems fine in so much as yesterday CH was turned on at 14 ish, by 3 house was at 17.5 degrees and up till 10 when CH went off, the boiler cycled for about 10 mins every 45 mins or so. I am happy with that!
That air vent obviously should be used to vent air. You should have mentioned it before rather than just complaining of air noises!
Can you use water pump pliars to turn it? Ideally holding the pipe as well to oppose the turning moment.
Tony
Can you use water pump pliars to turn it? Ideally holding the pipe as well to oppose the turning moment.
Tony
It is in the picture for all to see.
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
