Central heating issues

[Ian 1969]

Oh okay. Will probably clean the pump for today (see the pic, it's a wonder it even ran with the stuff from the water tank!), check it is okay, get the gaskets and cleaning agent to put in. Fit it all back together, run it and change the pipework in 2 weekends time when I drain the system again

 

[terryplumb]

Wonder what the inside is like , esp the impeller.

 

[Ian 1969]

Despite all that thick sludge etc, the motor itself seemed fine. No damage to the impeller and it turned smoothly. I put it all back together last night but tried re-filling this morning. All seemed to be going well, heating 3 radiators downstairs. There seemed like some air locks with noises coming from the pipes, I was venting any excess air intermittently from the vent pipe next to the cistern. Another problem has now occured as the boiler has totally stopped, I think the hot water from the taps is what was already there as the boiler does not seem to run at all now. I imagine that the amount of built up crud has caused a blockage in the pipes. I have put a water pipe on the end of the drain pipe from the radiator downstairs, back fed it whilst by girlfriend was checking the water tank and it throws water out of the overflow pipe. Not sure if it is now blocked?
Any ideas would be appreciated.
Many thanks

 

[terryplumb]

Have you bled all radiators ,including upstairs ones ? Are they all full of water ? When you say boiler isnt coming on ,do you mean its not firing up ( burning gas ) at all ?

 

[Ian 1969]

Hi Terry
Yes bled all the radiators downstairs then upstairs before starting the heating. They are all full and bled. Yes the boiler is not firing up, even for hot water as there is a separate Honeywell switch for hot water and heating. Just removed the front and the screw from the pump. The motor turns easily so no blockage there, but with both isolator valves undone the water is hardly trickling from the centre of the pump so must be blocked somewhere I reckon.

 

[terryplumb]

A blockage wouldnt stop the boiler from firing up on demand . when disconnecting pump ,have you touched any electrics at junction box ? Is the pump running ?

 

[Ian 1969]

No I have just checked all the fuses and junction box near the pump. Not sure what the white box with Drayton actuator on it. That wouldn't affect it would it.
I seem to be posting more and more problems. I have tried your magnet test again, and I was trying pipes further up and I don't know if I tested these, but they are all attracted to the magnet so will need to replaces these pipes as shown in red. Not sure if I need to replace under the floorboards to as they go down.
Not sure where to go from here? Another cold night

 

[Ian 1969]

PS The boiler stopped working before I disconnected the pump

 

[terryplumb]

Try turning the thermostat on the wall up from zero to above 20.
Just to rub it in Ian !!

 

[Gasguru]

Is the boiler pilot light visible?
Have you felt the pipes directly next to the boiler...are they red hot?
Have you got 240v going into the boiler?

I'd be cutting out the pipework around the combined feed connection to get an idea of the debris buildup.
I'd probably convert the system to a close coupled feed and vent using the H pattern. Once you achieve some circulation you can get the cleaner in there. Power flushing is a lottery and most of the time little is achieved...few do it well.

 

[Ian 1969]

Hi, got boiler working and all seemed great for a day. All radiators bled, bled the vent pipe behind the pump a few times to keep the water rising.
I was going to see what you guys thought of Sentinel X400 or X800 overnight, but probably wasting my time using it anyway.
You are right, the pipes will need changing as I think they are to far gone infected by now. i was hoping we could just get through this Winter with it as is for me to sort in the Spring.
Girlfriend would like a shower cubicle in the cupboard as it is off the bathroom, so we could away with all that pipework etc but I don't think a combi boiler is suitable for a 4 bed house with 13 radiators?
Latest problem now, went to go to bed last night and the pump was hot and off, radiators had started to cool down. Boiler was on so I removed the front cover from the pump, removed the pump centre screw, water came out and the pump impeller turned. Now as I removed the front cover from the pump and noticed the bottom white outlet (bottom of first pic) which I presume is a pressure outlet was all wet, and it had actually sprayed water onto the circuit board on the from the back. Not sure why they would design something like that?
I did try to dry it last night very lightly with a cool hair dryer, put it back onto the pump but the display light it for a split second and went off so I left it alone to dry overnight.
Tried again this morning and still the same. I have removed it and it still appears damp in there. Will drop it at my Moms to see if it will dry on a tray on her radiator I think.
I am thinking the cleaner mixed with the water may damage the electrical points on there though? The pump was still quite hot this morning despite the heating was turned off last night.
My other option for today is get a good used Grundfos 3 speed working pump locally (with wire in case a different plug) just to use temporarily to see if my original pump will work in a couple of days?
Any thoughts are grateful as always.
Thanks for reading
Kind regards Ian

 

[terryplumb]

Hi Ian , second pic shows brown discoloured area on the pcb( top right), as though its blown. That would be the opposite end to where you saw water. I have no idea what that little white thing is at the bottom , where you seen water, but water should not get to the electrics. I think you may draw a blank trying to dry it ,and will have to replace.
Regards Terry

 

[Ian 1969]

Hi, just to let you have an update. As you said Terry, no good with the original pump, I think the cleanser and water had got to the printed circuit so it had to be replaced.
I wanted to use a model without the electrical cover at the front, just in case the pipe blockage was causing the water/sludge to pressurize out of that tiny outlet because then I would be back to square one again with a scrap pump.
I purchased a used Grundfos pump, but when I got it home it looked suspect so returned it. I then purchased a new Grundfos Selectric which was the same model of output as the original but is just a 3 speed. Fitted it last night, and added some fresh cleaner as I had drained the old away. All went well, filled and bled no problem. Will run it as it is for a week now, but I must say I am pleasantly surprised as it seems to be heating all the rads on speed 2 quite well, but I have had to balance the radiators rather than leave them all open. I will drain next weekend, probably just fill with water for a few days to try and get rid of the cleanser (not planning on removing all the rads to flush out), and then drain again to then add the inhibitor.
As it seems to be working quite well at present I am hoping it will see us through the winter and change the pipework and re-work in the spring. Will then decide whether to fit a new Grundfos Alpha or stick with this one.
Many thanks for your help guys!
All the best
Kind regards Ian

 

[terryplumb]

Hi Ian ,good to hear all seems to be working well. You should consider fitting a magnetic filter ,whatever you decide to do later ,new boiler ,combi, or stick with the system you have ,the filter will remain .