Baxi won't stay on after pump change

[Claire P]

Please can someone help? I will start off with, about 2 weeks ago we removed the kitchen rad for refurb. The hot water on the Baxi Bermuda was working at the time. We replaced the rad, and we could hear it filling. We then, for the first time this year selected central heating from the controller upstairs. Nothing happened and we made note that the changeover valve wasn't sliding to the mid position. Ordered a new one (including a new 3 port) While waiting, we noticed the hot water wasn't getting hot. The pump was making awful noises so we bought a new one. Fitted the new motorised valve. When we changed the pump, we didnt drain down the whole system. We tied up the ballcock in the larger tank in the loft, then turned on the hot water taps and left to drain. Changed the pump which whirred into life no problem, all wiring correct.
Released the ballcock and we could hear the tank re-filling.
We switched on the hot water and heating, changeover went to mid position and pump whirred into life. 20 seconds later the back boiler stopped and there was "boiling sounds coming from the tank behind boiler. Now, we can only make the boiler fire up by turning it to max, but it only runs for a few seconds. We bled all rads, to discover we are only getting water out of the two downstairs ones, there is nothing coming out of all the upstairs ones. So, the boiler is not firing up from the switch upstairs now and we don't seem to have any pressure in the radiators upstairs.
Any advice will be appreciated. Thanks

 

[oilhead]

Bleed the pump. If nothing comes out, then look in the header tank, the small one. If that is full, you have a blockage where the cold feed enters the system, which would probably need a plumber to find and rectify.

 

[Claire P]

Apparently it's a self bleed pump, Flomasta. We have switched it on and off as advised to speed up the bleed process, makes no difference

 

[ianmcd]

sounds like you have a blocked cold feed, nothing to do with the pump or the 3 port valve or the boiler

 

[Claire P]

Any ideas where to start? lol

 

[ianmcd]

there will be a small tank in your loft probably, it is called a fill and expansion tank F&E, make sure that has water in it and the outlet of the tank is not blocked, then follow the outlet pipe to where it connects into your system, usually near the pump but not always, once you have found this connection try attaching a magnet to the area if it attracts that is where the blockage is and will need to be cut out and cleared

 

[Claire P]

Thanks Ian, will look at that next The level of water in the F and E is quite high

 

[CBW]

Any ideas where to start? lol

Yes, the tank in the loft. Check it’s getting water into it. You mentioned the larger tank you tied the ballcock, this is for the hot water cylinder and flow from taps only.

Take a photo of said f&e tank

 

[Claire P]

So, The Novice, you are saying we raised off the ballcock in the wrong tank? How would this affect the heating not working? Sorry for all the questions

 

[CBW]

So, The Novice, you are saying we raised off the ballcock in the wrong tank? How would this affect the heating not working? Sorry for all the questions

It wouldn’t affect the heating if you tied up the wrong tank, but when you changed the pump, or indeed from the original rad change, you might have been hearing the wrong one filling? Start simple and small, so check the water level/presence in the smaller of the two tanks in the loft, if this has water in it then you may have a blockage.

 

[ianmcd]

So, The Novice, you are saying we raised off the ballcock in the wrong tank? How would this affect the heating not working? Sorry for all the questions

Yes you were working on the wrong tank, if the f&E is full , when you removed the tree port valve water would have poured out, the fact that id didnt confirms you have a blocked cold feed, probably nothing was wrong with the pump or the 3 port valve that you changed

 

[Claire P]

Thank you both for your replies. There is indeed lots of water in the F and e tank, so i presume as you say that the rads etc haven't filled properly. We have just used a magnet on the pipes in the airing cupboard and found that it sticks right on the bend leading to the cold feed pipe to the pump. disconnected pipe from pump and opened the shut off valve and no water came through the pump. So, do you think I found my blockage?

 

[Madrab]

Yup, the blockage in the copper pipe is magnetic (magnetite), it's a typical failure point of an older open vented system. You currently have a half filled system and nothing for the pump to circulate. Don't run the new pump dry, as that can damaged it.

As @ianmcd suggests, that section of pipe will need cut out and cleared/replaced and the system inhibited/filled and bled again.

 

[Claire P]

We have tried a rod in the pipe, it comes out covered in black muck but still no water, so it is looking like we will have to cut pipe and rejoin using a compression fitting. We haven't ran the pump, only long enough yesterday to realise the back boiler wasn't staying lit and there must be a problem. Thanks you all soo much for your advice, looks like we are heading in the right direction at least

 

[ianmcd]

We have tried a rod in the pipe, it comes out covered in black muck but still no water, so it is looking like we will have to cut pipe and rejoin using a compression fitting. We haven't ran the pump, only long enough yesterday to realise the back boiler wasn't staying lit and there must be a problem. Thanks you all soo much for your advice, looks like we are heading in the right direction at least

Yes you definately have a blocked cold feed and as @Madrab says , dont run the system dry, you will just cause damage , when you clear the blockage run some cleanser through the system, then drain and add inhibitor, you will have to physically clear the blockage first though