Central Heating (or lack of it) problems
Discussion
Morning All,
Got up this morning and thought :scratchchin: "Hmm, Chez Sheepy is a bit chilly" Checked the radiators and found them cold. Quick check in boiler cupboard showed system thinks its running just hot-water which was the correct setting for the time (heating should have been on 6-6:30 with hot-water only after 6:30). Clicked the advance to bring heating back on, boiler fired up for a few seconds and then shut off. Still no heat in radiators.
Next checked first rad in system for air (and bled quite a bit out). Also checked expansion tank for water (tank valve drips, so the water is normally kept turned-off). This was fine, so now I looked further into the boiler cupboard.
Pipe into boiler quite warm, pipe from boiler hot: OK
Pump buzzing away happily: OK
Two-way valve motors between W(ater) and H(eating) happily: OK
Pipes into valve are all cold: :eek:
Check back: Pipe into pump hot, pipe from pump hot but cooling rapidly until reaches valve where it is cold.
Touch pump body : Owww, f:censored:k, that's bloody hot! :idea: I think it might be the pump :hehe:
Am I right? Of is there something else I need to check before I start taking things apart?
Cheers,
Sheepy
Got up this morning and thought :scratchchin: "Hmm, Chez Sheepy is a bit chilly" Checked the radiators and found them cold. Quick check in boiler cupboard showed system thinks its running just hot-water which was the correct setting for the time (heating should have been on 6-6:30 with hot-water only after 6:30). Clicked the advance to bring heating back on, boiler fired up for a few seconds and then shut off. Still no heat in radiators.
Next checked first rad in system for air (and bled quite a bit out). Also checked expansion tank for water (tank valve drips, so the water is normally kept turned-off). This was fine, so now I looked further into the boiler cupboard.
Pipe into boiler quite warm, pipe from boiler hot: OK
Pump buzzing away happily: OK
Two-way valve motors between W(ater) and H(eating) happily: OK
Pipes into valve are all cold: :eek:
Check back: Pipe into pump hot, pipe from pump hot but cooling rapidly until reaches valve where it is cold.
Touch pump body : Owww, f:censored:k, that's bloody hot! :idea: I think it might be the pump :hehe:
Am I right? Of is there something else I need to check before I start taking things apart?
Cheers,
Sheepy
Are you sure the diverter valve is working. In the summer, when you dont use central heating, the diverter valve is closed to rads, when you first put it on for the winter, it has to open.
Mine has ceased up twice over the years, most likely failure I think. If the pump is running, that eliminates that.
Mine has ceased up twice over the years, most likely failure I think. If the pump is running, that eliminates that.
406 said:
Have you ble dthe pump? The big screw in the center just needs to be turned anti clockwise a little bit. You could also try tapping the pump to see if it's stuck.
HTH
Dave
406
If you take off the end cap, you will be able to see the spindle turning, if it dont, stick a screwdriver in and give a turn, if it doesnt turn, and still buzzez, its buggered, simple to fit, if it is.
I should have added that the system was working fine until (atleast) yesterday evening. The rads were warm yesterday morning, and we had enough hot water for my wife to have a bath last night.
Don't know if the rads were warm last night, we were in the pub at the time
As for bleeding the pump, must admit I'd never heard of that before. My pump is fitted such that the flow through it is vertical, does this make it less likely to need bleeding?
Fortunately my system has two isolating valves, one either side of the pump. Will make removal/refit easier.
As I'm at work right now, and Wickes is on the way home, I'm tempted to buy a new one on the way (I've taken the afternoon off) and then investigate further. If I get my pump going again, I'll either keep the new one (as a spare) or get my money back.
Sheepy
Don't know if the rads were warm last night, we were in the pub at the time
As for bleeding the pump, must admit I'd never heard of that before. My pump is fitted such that the flow through it is vertical, does this make it less likely to need bleeding?
Fortunately my system has two isolating valves, one either side of the pump. Will make removal/refit easier.
As I'm at work right now, and Wickes is on the way home, I'm tempted to buy a new one on the way (I've taken the afternoon off) and then investigate further. If I get my pump going again, I'll either keep the new one (as a spare) or get my money back.
Sheepy
OK, so how the f
k do I get the nuts holding the pump to the two isolating valves undone? Bought the right wrench, but I can't stop the bastard pump from turning as I pull (or if I manage to stop it turning, the wrench slips).
Just applied plus-gas to see if that helps, and whilst its soaking in, thought PH plumbers might have some ideas.
Sheepy
k do I get the nuts holding the pump to the two isolating valves undone? Bought the right wrench, but I can't stop the bastard pump from turning as I pull (or if I manage to stop it turning, the wrench slips). Just applied plus-gas to see if that helps, and whilst its soaking in, thought PH plumbers might have some ideas.
Sheepy
Sadly pump removal is rarely easy. I often just cut the nut nearly through and then split it with a screwdriver. It's just a matter of replacing the nut then (for which you'll have to buy a couple of new valves).
It certainly sounds like poor circulation in your system so I would initially suspect the pump.
It certainly sounds like poor circulation in your system so I would initially suspect the pump.
If it is the pump try replacing the capacitor first before you replace the whole pump. It's not uncommon for the capacitor to fail, which causes the pump to not start; you can spin it with a screwdriver and it then goes but lacks torque, runs slow and doesn't pump much. You can get a replacement capacitor from CPC or Farnell.
Evening all,
Chez Sheepy all snug and warm again!!!
In the end I bought two new valves and just stripped the old pump with the valves in one lot! So much for using isolation valves to allow easy pump removal!!
Old pump was somewhat broken. Impeller had detached itself from the spindle (hence pump seemed to be running, but nothing was happening). Pump had manufacture date of Apr/87, so can't complain too much.
Just to prove it never rains but it pours, one of rads decided to spring a leak once I got the system up and running again
Fortunately it is in the spare bedroom. However this will mean I have had to replace the first and last rads in the system. I think it might be prudent for me to replace the other five over the next year or so.
Thanks to all for the advice
Sheepy
Chez Sheepy all snug and warm again!!!
In the end I bought two new valves and just stripped the old pump with the valves in one lot! So much for using isolation valves to allow easy pump removal!!
Old pump was somewhat broken. Impeller had detached itself from the spindle (hence pump seemed to be running, but nothing was happening). Pump had manufacture date of Apr/87, so can't complain too much.
Just to prove it never rains but it pours, one of rads decided to spring a leak once I got the system up and running again
Fortunately it is in the spare bedroom. However this will mean I have had to replace the first and last rads in the system. I think it might be prudent for me to replace the other five over the next year or so. Thanks to all for the advice
Sheepy
Sheepy,
Leaking rads is something that shouldn't really happen. If they have rusted it is an indication that the system is somehow re-aerating with the free oxygen required to rust the steel rads. The most common reason, probably, is 'pumping over'. Take a look at your CH header in the roof (probably) when the system is running and see if water is running out of the vent pipe above the tank. If so try turning the pump down although that is treating symptom rather than cause. Another reason for rusting is a constant supply of fresh water, possibly from a leak somewhere. Under a downstairs floor?? Was there a lot of rusty sludge in the pump? Bear in mind that the boiler heat exchanger may be cast-iron.......expensive.
Sorry to worry you, it may not be this at all, but it's probably worth investigating. Normal CH water doesn't rust things.
Leaking rads is something that shouldn't really happen. If they have rusted it is an indication that the system is somehow re-aerating with the free oxygen required to rust the steel rads. The most common reason, probably, is 'pumping over'. Take a look at your CH header in the roof (probably) when the system is running and see if water is running out of the vent pipe above the tank. If so try turning the pump down although that is treating symptom rather than cause. Another reason for rusting is a constant supply of fresh water, possibly from a leak somewhere. Under a downstairs floor?? Was there a lot of rusty sludge in the pump? Bear in mind that the boiler heat exchanger may be cast-iron.......expensive.
Sorry to worry you, it may not be this at all, but it's probably worth investigating. Normal CH water doesn't rust things.
Hi Ferg,
Bear in mind the rads have been in the system since 1988. Also, I do find that the system uses a slight bit of water. Some of the valves leak a little bit (not enough to drip, but enough to evaporate leaving mineral deposits behind).
So I guess its a mixture of age and a bit of corrosion.
Should I add something like fernox to the header tank?
Sheepy
Bear in mind the rads have been in the system since 1988. Also, I do find that the system uses a slight bit of water. Some of the valves leak a little bit (not enough to drip, but enough to evaporate leaving mineral deposits behind).
So I guess its a mixture of age and a bit of corrosion.
Should I add something like fernox to the header tank?
Sheepy
cant believe you've got the heating on allready.... what you going to be like when it really is cold.... especially being Sheepys 
BB
Fenox or whatever its called will help but I would recon the whole system should be flushed through a couple of times, and bleed. will help it and stop any pipe banging too
BB
Ballistic Banana said:
Hi BB, Well the heating is only on for a few minutes. IMHO its a good idea to stick it on (briefly) early, because most problems occur when the system is turned back on, and I'd rather spend a day plumbing in October whilst Mrs S just wears another cardi, than trying to fix a problem in December whilst ice forms in places it shouldn't and Mrs S gets molested by penguins
Ferg, I'll follow your advice and see what happens!!
Sheepy
of to turn mine on for a few mins, should burn the dust of the Rads 
If you had British Gas cover, all that work would be done free of charge, even replacing leaking rads as well..
Money well spent. Mine conked out one cold miserable winter evening. Had a guy round first thing next morning, within the hour, new pump new diverter, all working tickerty boo in no time.
Cover may sound expensive, but divide it by pints of beer or packs of fags,...........
Money well spent. Mine conked out one cold miserable winter evening. Had a guy round first thing next morning, within the hour, new pump new diverter, all working tickerty boo in no time.
Cover may sound expensive, but divide it by pints of beer or packs of fags,...........
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