I've just replaced the 40yr old pump, the outlet port on it was blocked solid! Now there is flow to all rads n they all get hot BUT with the pump set on 1 it is pumping over into the FE tank (nothing is coming down the overflow). The vent is teed off the elbow into the HW tank and rises into the loft in 22mm, the FE tank is 3ft above the cold tank, what do you think experts?
Can a CH pump wear out?
- Thread starter DIYedboy
- Start date
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quite likely you have general accumulations of sludge in all the pipes and rads. You might check all the rad valves are wide open as a temporary aid while you get on with cleaning it.
if you hold a strong magnet to the copper pipes it will be attracted to areas holding black sediment. If the are very bad you can cut out the blocked sections and replace with new pipe.
if it is pumping over, start by reducing the speed of the pump; then tie up the ball valve, then bale and sponge out all the mud from your F&E tank, and drain a bucket of water out, then add a litre of Sentinel X400 which is a mild sludge-loosener, refill it and run it for 4 weeks before draining and rinsing which will remove the loosened sludge. You will know it is working if the water turns inky black. The chemical will cost you £15. This is a very cheap and easy way of removing some of the deposits, and may save you the cost of a Powerflush later.
If you can do basic DIY plumbing and can afford £100, fit a Magnaclean as well, I guarantee you will be amazed and delighted at how much black sludge it traps. It continues working for many years and you empty out the sludge it has trapped
remember you must add an inhibitor such as X100 when you refill.
If you post a pic of the pipes showing the vent pipe, the F&E pipe and the pump, we may see a pipe layout error that you could alter.
if you hold a strong magnet to the copper pipes it will be attracted to areas holding black sediment. If the are very bad you can cut out the blocked sections and replace with new pipe.
if it is pumping over, start by reducing the speed of the pump; then tie up the ball valve, then bale and sponge out all the mud from your F&E tank, and drain a bucket of water out, then add a litre of Sentinel X400 which is a mild sludge-loosener, refill it and run it for 4 weeks before draining and rinsing which will remove the loosened sludge. You will know it is working if the water turns inky black. The chemical will cost you £15. This is a very cheap and easy way of removing some of the deposits, and may save you the cost of a Powerflush later.
If you can do basic DIY plumbing and can afford £100, fit a Magnaclean as well, I guarantee you will be amazed and delighted at how much black sludge it traps. It continues working for many years and you empty out the sludge it has trapped
remember you must add an inhibitor such as X100 when you refill.
If you post a pic of the pipes showing the vent pipe, the F&E pipe and the pump, we may see a pipe layout error that you could alter.
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God knows how to post photos of the system (but he aint told me!). The house is a victorian two up two down, boiler is a baxi bermuda back boiler, pump is on the return, HW cylinder is upstairs (vent tees out of flow elbow into cylinder and rises in 22mm into loft ). Not sure where flow pipe is, but will look tonight when adding the X400 to the new water which is already orange.
orange water is a bad sign as it shows active rust. this will be because the pumping over is like a fountain, dissolving air bubbles as it pours into the F&E. If it does not stop pumping over soon:
add some X100 to reduce corrosion
see if you can increase the height of the vent pipe so that it will have to rise further before it can get over the bend.
F&E tank does not need to be higher than the cold water tank, it is preferable to have the top of it lower than the top of the CWC. The lower the F&E is, compared to the bend at the top of the vent pipe, the less prone it is to pumping over.
//www.diynot.com/forums/viewtopic.php?t=129539
add some X100 to reduce corrosion
see if you can increase the height of the vent pipe so that it will have to rise further before it can get over the bend.
F&E tank does not need to be higher than the cold water tank, it is preferable to have the top of it lower than the top of the CWC. The lower the F&E is, compared to the bend at the top of the vent pipe, the less prone it is to pumping over.
//www.diynot.com/forums/viewtopic.php?t=129539
Whilst orange water is definitely A Bad Thing, I think this part of your post will confuse people, because:
1. "Active rust" is nothing other than "rust".
2. The orange colour isn't caused by pumping over.
This would be a complete waste of money when the system is full of sludge and rust.
That's a bit like putting a sticking plaster on a gunshot wound. The problem needs to be solved.
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DIYedboy - if you can't take and post a photo, then just sketch the pipe layout and post that.
If you can't post a sketch then describe the pipe layout in words.
Fudge me Softus, how does a sketch on a bit of paper get into a forum? ( why do I have to be such a computertwat?). I'll have to describe the pipe run, I've just looked at the return out of the HW cylinder, it is reduced down to 15mm n drops down into floorboards (a 15mm feed down from the FE tank also connects to that elbow). Roughly 8 feet from that I can see it has joined the 22mm return going back downstairs (the upstairs rad return (also 15mm) also connects to this 22mm pipe. Hopefully if you piece this and my previous post together you will now have a full picture of the full system.
Tonight I cleaned out the expansion tank all covered in brown sludge, added the X400 and refilled, set the pump to 3 and watched the expansion pipe pour hot water water up into it (but not as high as the overflow), the way I see it, might as well have the pump on max for a month and hopefully blast a lot of sludge out when I drain down.
Over to you Softus n other experts
Tonight I cleaned out the expansion tank all covered in brown sludge, added the X400 and refilled, set the pump to 3 and watched the expansion pipe pour hot water water up into it (but not as high as the overflow), the way I see it, might as well have the pump on max for a month and hopefully blast a lot of sludge out when I drain down.
Over to you Softus n other experts
I wouldn't increase the pump speed if it's pumping over on the lowest setting.
The pump doesn't operate how you think - it's incapable of "blasting" anything.
The important section/area of pipework involves the following three items:
1. Vent.
2. Cold feed connection into the circuit.
3. Pump.
...and it's best if they're connected in the order listed (in the direction of flow).
I see that your cold feed connects to a tee at the return emerging from the cylinder, and the vent connects to a tee at the flow that goes into the cylinder. If the pump is before the vent then this is a significant factor in the pumping over.
If you've managed to get X400 into the system (as opposed to merely into the F&E cistern), then there's a chance that it will loosen enough of the sludge/rust/debris such that it will stop pumping over during the next few days/weeks. However, at some point you need to bite the bullet and change the pipework.
The pump doesn't operate how you think - it's incapable of "blasting" anything.
The important section/area of pipework involves the following three items:
1. Vent.
2. Cold feed connection into the circuit.
3. Pump.
...and it's best if they're connected in the order listed (in the direction of flow).
I see that your cold feed connects to a tee at the return emerging from the cylinder, and the vent connects to a tee at the flow that goes into the cylinder. If the pump is before the vent then this is a significant factor in the pumping over.
If you've managed to get X400 into the system (as opposed to merely into the F&E cistern), then there's a chance that it will loosen enough of the sludge/rust/debris such that it will stop pumping over during the next few days/weeks. However, at some point you need to bite the bullet and change the pipework.
now it is only black as mud, give it some time and it may get as thick as mud too.
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