No hot water since drain-down
- Thread starter mpirie
- Start date
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Hi again !
The water in the central heating will squirt out, though I'm not brave enough to let it come out so forcefully !!
I drained and refilled again, but have the same problem.
The CH works fine, all rads heat up, and have been bled several times.
When I switch on the hot water, the boiler comes on for a while then the cut out trips and the panel of the boiler is hotter than norm, hence the suspicion that an air lock (or blockage) is stopping the water circulating in the heat exchanger.
Where should I look for blockages? I thought the small header was for the central heating only......is the hot water fed from the main tank/main?
Thanks.
The water in the central heating will squirt out, though I'm not brave enough to let it come out so forcefully !!
I drained and refilled again, but have the same problem.
The CH works fine, all rads heat up, and have been bled several times.
When I switch on the hot water, the boiler comes on for a while then the cut out trips and the panel of the boiler is hotter than norm, hence the suspicion that an air lock (or blockage) is stopping the water circulating in the heat exchanger.
Where should I look for blockages? I thought the small header was for the central heating only......is the hot water fed from the main tank/main?
Thanks.
let me check... when you turn on the hot taps:
Does cold water come out?
or
Does nothing come out?
Also
Please read through the earlier posts and check (1) that you have answered all the questions (2) that you have tried all the suggestions
and say what happened when you did.
You say the radiators are all getting hot, so you mean the pump is working OK? And all the rads are hot all over, no cold patches?i
have you got a 3-port valve? Feel the 3 pipes on it to see which are hot.
Some pictures would be useful, especially round the cylinder, to show the pump, electric valve, and pipe layout.
You didn't get any black water or sediment out, when you drained the rads, but you got brown water and brown sediment? Is that right?
Have you got an immersion heater on the cylinder?
Does cold water come out?
or
Does nothing come out?
Also
Please read through the earlier posts and check (1) that you have answered all the questions (2) that you have tried all the suggestions
and say what happened when you did.
You say the radiators are all getting hot, so you mean the pump is working OK? And all the rads are hot all over, no cold patches?i
have you got a 3-port valve? Feel the 3 pipes on it to see which are hot.
Some pictures would be useful, especially round the cylinder, to show the pump, electric valve, and pipe layout.
You didn't get any black water or sediment out, when you drained the rads, but you got brown water and brown sediment? Is that right?
Have you got an immersion heater on the cylinder?
Hi John,
Water comes out of the hot taps, but it's cold, as in hasn't been heated.
The water that drained out had a rusty tint to it, but it was still clear. If you let the water sit, you could see a light brown deposit left.
The small expansion tank fills and drains fine, i turned the main supply off, and let the expansion tank drain through the radiators.
All the radiators heat up fine, no cold spots, and all have been bled.
The only pump I have is for the CH, I think the hot water is a gravity system? I don't have a 3 way valve anywhere.
I have an immersion heater in the hot tank and it heats the water ok.
I allowed the system to refill by reversing the order I turned all the valves off in ie turned off the feed from the main tank to the taps, then the hot water valve beside the hot tank and finally the main supply into the house.
Thanks,
Mike
Water comes out of the hot taps, but it's cold, as in hasn't been heated.
The water that drained out had a rusty tint to it, but it was still clear. If you let the water sit, you could see a light brown deposit left.
The small expansion tank fills and drains fine, i turned the main supply off, and let the expansion tank drain through the radiators.
All the radiators heat up fine, no cold spots, and all have been bled.
The only pump I have is for the CH, I think the hot water is a gravity system? I don't have a 3 way valve anywhere.
I have an immersion heater in the hot tank and it heats the water ok.
I allowed the system to refill by reversing the order I turned all the valves off in ie turned off the feed from the main tank to the taps, then the hot water valve beside the hot tank and finally the main supply into the house.
Thanks,
Mike
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I think the layout round the cylinder is most likely the trouble.
But round the boiler, and the F&E tank in the loft (including inside) may help.
Also any vents that go up from near the cylinder or the boiler into the loft.
But round the boiler, and the F&E tank in the loft (including inside) may help.
Also any vents that go up from near the cylinder or the boiler into the loft.
Hi John,
Can't post images on this board, but I did take some of the cylinder and boiler.
I tried ramming a length of twin and earth down both cold water feeds from the main tank, and on the CH feed from the header tank.
Still not joy...CH is fine, hot water trips the cutout before the water heats up
Is there a way to back flush the hot water side, to blow out any obstructions?
Thanks,
Mike[/img]
Can't post images on this board, but I did take some of the cylinder and boiler.
I tried ramming a length of twin and earth down both cold water feeds from the main tank, and on the CH feed from the header tank.
Still not joy...CH is fine, hot water trips the cutout before the water heats up
Is there a way to back flush the hot water side, to blow out any obstructions?
Thanks,
Mike[/img]
in this picture,
http://i191.photobucket.com/albums/z228/mpirie0457/DSCN1326.jpg
a pipe (far right) rises to a service valve and stop end. Can you bleed any air out of here?
http://i191.photobucket.com/albums/z228/mpirie0457/DSCN1326.jpg
a pipe (far right) rises to a service valve and stop end. Can you bleed any air out of here?
Well your HW feed from the boiler isn't pumped, it uses the "gravity" connections.
If venting the pipe as JohnD suggests doesn't work, do you have an aquavac, or carpet cleaning vac? If so try sucking at the vent pipe in the loft.
The next thing could be to take a thermostat out of the boiler to let it boil - not recommended.
If venting the pipe as JohnD suggests doesn't work, do you have an aquavac, or carpet cleaning vac? If so try sucking at the vent pipe in the loft.
The next thing could be to take a thermostat out of the boiler to let it boil - not recommended.
As JohnD said - that your vent. Get vented young padawan.
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