Overheating water pump (after draining all water tanks in the loft)

[Toni.34]

I had to drain all water tanks in the loft as the gate valve open seized (in the air cabinet) and couldn't turn it off. Then replaced all radiators with new ones and done some pipe work too. Yesterday refilled the system and bleed all radiators (from bottom to top). It took me almost a day to refill all rads which I found strange?

Current situation is as fallows:

1- Both of the tanks are filled with water in loft.
2- All rads are filled with water and bleeded.
3- No water coming out from cold taps in the bathroom.
4- Toilet's cistern is filling too slow in the bathroom.
5- Hot water taps are running normally in the bathroom.
6- Started the heating the system and pump started working normally I heard some noises from the pipes and shut the heating system.
7- Started the heating system again and let it run for about 10 minutes until I notice the water pump is too hot to touch (hotter than the copper pipe).
8- When heating was on radiators went hot quickly and thanks god no any leaks.
9- I also tried to bleed the water pump itself but did not hear any hissing noise after unscrewing.

Can air lock in the heating systems cause water pump overheating ?
Is it normal that it took almost a day to fill all rads?

Thank you in advance,

 

[stem]

Can air lock in the heating systems cause water pump overheating ?

If the radiators are working as your post implies, then the pump will get hot due to the hot water it is circulating and heat from its motor. If you had an airlock there wouldn't be any circulation and your radiators would not heat up.

Is it normal that it took almost a day to fill all rads?

No it's not, but did you open all valves fully including any motorised valve/s whilst filling the system?

 

[Agile]

Do you have isolation valves on the pump?

Are they open?

Tony

 

[Toni.34]

I had thought the same if the pump was not working it would not be any circulation and rads wont heat up.

Yes I did open all valves on rads nothing else

Yes I think I have isolation valves on the pump and I didnt touch them at all.

 

[stem]

The cold taps & toilet in the bathroom may be supplied from the feed tank in the loft. If so, you may have an airlock or have dislodged some dirt in the pipe from the tank causing a blockage. If you can run a hose pipe from a working tap connected to the cold main such as in the the kitchen, to one of the bathroom taps, open both taps fully you may be able to blow it through.

 

[Toni.34]

I

The cold taps & toilet in the bathroom may be supplied from the feed tank in the loft. If so, you may have an airlock or have dislodged some dirt in the pipe from the tank causing a blockage. If you can run a hose pipe from a working tap connected to the cold main such as in the the kitchen, to one of the bathroom taps, open both taps fully you may be able to blow it through.

I will try that. Thank you. It is highly likely fix the issue.

My main concern is water pump. I don't want to burn it down or cause fire

 

[Toni.34]

If the radiators are working as your post implies, then the pump will get hot due to the hot water it is circulating and heat from its motor. If you had an airlock there wouldn't be any circulation and your radiators would not heat up.



No it's not, but did you open all valves fully including any motorised valve/s whilst filling the system?

I opened only all radiators valves. I did not open the water pump. Did I have to open the pump as well ?

 

[Toni.34]

Do you have isolation valves on the pump?

Are they open?

Tony

Yes I think I have isolation valves on the pump and I didn't touch them at all.

 

[stem]

If you are that worried, you could go around to a friend / neighbour / relatives home and check out how hot their pump is when the heating is running and the boiler is at a similar setting to yours. You may well find that it's as hot as yours is.

 

[Toni.34]

If you are that worried, you could go around to a friend / neighbour / relatives home and check out how hot their pump is when the heating is running and the boiler is at a similar setting to yours. You may well find that it's as hot as yours is.

I let the boiler run for an hour last night until I heard banging noises from the pipe between boiler and the pump. It must be an air lock. What do you think ? I saw a guy undoing nuts that connects pump to the pipes to bleed the air. Is that right way to do it ?

No air is coming out from rads.

When I switched hot water ON then heard glupping sound from pipe that goes to hot water tank and boiler stopped working. I have hot water issue as well

The only good news is that I managed to get cold taps running again with a huge blow



Thank you

 

[stem]

It's not unusual when first running a system that has been drained get pockets of air that collect and then get dislodged, it usually settles down after a few days.

 

[Toni.34]

It's not unusual when first running a system that has been drained get pockets of air that collect and then get dislodged, it usually settles down after a few days.

Last night I opened the drain valve and let the water run for about 10 minutes. After that run the boiler and the boiler worked for 10-15 minutes then get 2 bangs from the pipe then boiler stopped automatically and overheating led went ON. I think there is still air in the system. Shall I fully drain the system and fill it again this time properly (I did not open motorized valve and took almost a day to fill all rads before ) ? Or shall I wait for a few days to let the system settles down?

Thank you

 

[stem]

Every time you open up the system you will let more air in. If the system is running then leave it alone, the air will work its way out eventually.

If it's stopped working now again because of your tinkering, then that will require further investigation.