New Central Heating Pump

[poolielad]

Hi, I have just fitted a new central heating pump, When fitting it I had to do a full draindown because because one of the isolation stops wasnt working (the ones at the top and bottom of pump. Fitted pump and drained all back up, put water on and now the pump is red hot.... I have tried bleeding pump but water just seem to be coming out all the time!!! Surely the pump shouldnt be running hot, and how can I bleed pump when I cant turn water isolations off??
PS, I am not a Plumber, just thought I could do this job myself.

 

[cross thread]

Turn the pump off,now try bleeding,you can also crack one of the unions slightly

 

[poolielad]

Turn the pump off,now try bleeding,you can also crack one of the unions slightly

Thanks for replying, when you say turn pump off, do you mean at electric box box stairs?

 

[HERTS P&D]

Is there an air bleed valve near the cylinder?

Post poictures.

Andy

 

[oldbuffer]

1. The pump will run as hot as the water in it, so likely to be around 70 to 80 degrees.
2. Generally the pump is controlled by the boiler. As air bleeding should anyway be done with the system off, switch off the boiler, wait 15 minutes, then bleed the pump.
3. The pump should be bled with the pump valves open. If they are shut, there is no pressure to force air out. If the pump has a central (often chromed) screw with a screwdriver slot in it or hexagon round it, slacken the screw / nut. Any air should come out, and it's likely so will some water so have some old towels handy. Many modern pumps are self bleeding - see the instructions which came with your pump. If the foregoing doesn't help, do as cross thread suggests and crack open one of the pump valve nuts (with the valves open). Pick the highest one you can.
4. If your system has a feed and expansion (F&E) tank in the loft, you may have drained down any sludge / debris in the tank and caused a system blockage. Check the level of water in the F&E tank. Should be about 4" / 100 mm deep and covering the outlet.

 

[poolielad]

Is there an air bleed valve near the cylinder?

Post poictures.

Andy

 

[poolielad]

Everything seems to be working fine, radiators balanced out so they seem loads better, no noise from new pump, it’s just the pump is hot, but some people say that’s ok and some say it shouldn’t be hot!!!

Also, could someone please tell me what this switch is for?

 

[poolielad]

1. The pump will run as hot as the water in it, so likely to be around 70 to 80 degrees.
2. Generally the pump is controlled by the boiler. As air bleeding should anyway be done with the system off, switch off the boiler, wait 15 minutes, then bleed the pump.
3. The pump should be bled with the pump valves open. If they are shut, there is no pressure to force air out. If the pump has a central (often chromed) screw with a screwdriver slot in it or hexagon round it, slacken the screw / nut. Any air should come out, and it's likely so will some water so have some old towels handy. Many modern pumps are self bleeding - see the instructions which came with your pump. If the foregoing doesn't help, do as cross thread suggests and crack open one of the pump valve nuts (with the valves open). Pick the highest one you can.
4. If your system has a feed and expansion (F&E) tank in the loft, you may have drained down any sludge / debris in the tank and caused a system blockage. Check the level of water in the F&E tank. Should be about 4" / 100 mm deep and covering the outlet.

Thank you, regarding number 4, when I drained down there was lots of black sludge in bottom of little tank in loft, is that normal?? I managed to clean it out before refilling and putting the inhibitor in….

 

[HERTS P&D]

The switch is for you immersion, there is an air bleed valve upright next to the 3 port valve.

Andy

 

[poolielad]

The switch is for you immersion, there is an air bleed valve upright next to the 3 port valve.

Andy

Daft question I know lol, but does that need to be switched on, or what does it even do??

And which is port 3 ?

 

[HERTS P&D]

You open it to let the air out and the silver box with 3 pipes going to it is the 3 port valve.

Andy

 

[poolielad]

You open it to let the air out and the silver box with 3 pipes going to it is the 3 port valve.

Andy

So which one would be the bleed thing please?

 

[poolielad]

And regarding switch for immersion, what does it do, and should it be switched on, we have never had it switched on because I don’t know what it does

 

[oldbuffer]

1. The manual air bleed valve is at the end of the vertical pipe in the first of your pictures above. Slacken the brass top screw with a screwdriver no more than a turn or two, and any air should hiss out. When water starts to bubble out, do the screw up again.
2. The screwdriver slot in your second picture of the horizontal pipe going into your cylinder is an isolation valve. It shouldn't be there, but leave it alone.
3. An immersion heater heats the water in the cylinder using electricity, rather than your boiler. Useful if the boiler breaks down, but expensive to run (3 to 4 times the cost of the same heating by gas). Worth turning it on with a cold cylinder just to check its working.

 

[poolielad]

1. The manual air bleed valve is at the end of the vertical pipe in the first of your pictures above. Slacken the brass top screw with a screwdriver no more than a turn or two, and any air should hiss out. When water starts to bubble out, do the screw up again.
2. The screwdriver slot in your second picture of the horizontal pipe going into your cylinder is an isolation valve. It shouldn't be there, but leave it alone.
3. An immersion heater heats the water in the cylinder using electricity, rather than your boiler. Useful if the boiler breaks down, but expensive to run (3 to 4 times the cost of the same heating by gas). Worth turning it on with a cold cylinder just to check its working.

Thank you, so would I bleed that while the heating is on and pump is running, or do I need to turn electricity off to do it??