I had to remove a radiator with stuck valves so partially drained the system sealed the pipe and refilled. Since then every time the heating is put on it loses pressure over a few hours. I've tried to see if there is water coming out of the pressure release valve and there doesn't seem to be but may have done. I'm told it may be the pressure release valve and its relatively cheap. So can someone tell me how to replace it please.
Worcestor Bosch 40 cdi losing water pressure
- Thread starter kinhell
- Start date
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A PRV will not tend to just fail unless something has activated it.When refiling did you accidentally overpressurise it?
With system pressure cold at 1-1.5bar what does the pressure rise too when the heating is running?
If the pressure rises quickly up to three then discharges it indicates the expansion vessel is faulty (may simple need recharging or replacing)
You may get away with just removing the PRV innards and cleaning the seal and valve itself. You could try putting a bag over the outside pipe to see what comes out.
It's possible you could have disturbed a pipe when you replaced the rad
With system pressure cold at 1-1.5bar what does the pressure rise too when the heating is running?
If the pressure rises quickly up to three then discharges it indicates the expansion vessel is faulty (may simple need recharging or replacing)
You may get away with just removing the PRV innards and cleaning the seal and valve itself. You could try putting a bag over the outside pipe to see what comes out.
It's possible you could have disturbed a pipe when you replaced the rad
I think I must have over pressurised it. The expansion vessel is at the right pressure. How do I take the PRV off? I can drain the boiler easily as its in the loft so highest point. Is it a case of just pulling the clip out and it should come out or do I have to do anything else?
Drain it pull clip and undo connection off to outside and out it comes.
You can either replace it or save yourself some money and try cleaning it out.
They can be a bit awkward
You need to support the brass section and get some grips on the very thin black plastic ring below the red manual knob and unscrew it.
Just give the black rubber seat a good clean removing and of the crud and clean the brass seat inside with a light emery cloth.
I do this most of the time it works. sometimes if the valve is warped they don't seat right again and you need to swap the PRV but it's definitely worth a try
You can either replace it or save yourself some money and try cleaning it out.
They can be a bit awkward
You need to support the brass section and get some grips on the very thin black plastic ring below the red manual knob and unscrew it.
Just give the black rubber seat a good clean removing and of the crud and clean the brass seat inside with a light emery cloth.
I do this most of the time it works. sometimes if the valve is warped they don't seat right again and you need to swap the PRV but it's definitely worth a try
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I've topped up the system and checked the overflow and there doesn't seem to be any leak. I took the end off the condensate pipe and noticed a lot of water comes out in bursts. I have a funny feeling its losing pressure through there and not the PRV. Is this possible?
Yes more than possible. Heat exchanger sounds like its cracked, normally happens when the boiler overheats or runs on very low pressure / powercuts/ pump failure. I've been doing loads.
Pressurize the boiler, close the flow and return and if you lose pressure it'll be the heat exchanger.....get Worcester to do it on a fied price repair.
Pressurize the boiler, close the flow and return and if you lose pressure it'll be the heat exchanger.....get Worcester to do it on a fied price repair.
yes, the primary heat exchanger is cracked. The guy who normally services it took it all apart today and showed me. He said it was £330 +vat just for the heat exchanger and recommended I rang Worcester Bosch for a fixed price quote. They are coming out tomorrow to sort it. I've finally succumb and took out their monthly policy for £23 which will include all parts and labour and will cover their visit tomorrow and also a service at some point. My gas guy said it was probably a manufacturing fault and probably not due to the pressure dropping too low as it would cut out but its too much of a coincidence that it happened just when I refilled it after draining it all.
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