Added a radiator to a sealed worcester 28 cdi system, bringing it upto 10 rads. Took new rad off a rad in the back room with plastic piping. However after fitting the rad the pressure drops by sometimes upto 1 bar a day to under 0.5. The CH/Hot water still works, but hot water has twice gone cold during hot water flow. Switched off demand and tried again and it works fine. Thought it was the pipes linking the new rad which is under solid wood floor, did not want to lift floor so decided to cut the plastic piping and sealed them (removing new rad from system). Pressure stayed at 1.5 bar, however after two days pressure began falling again to above levels, checked the fittings on the back rad and there is no leaks. Looking for any clues?
Bar Pressure Dropping on Worcester 28 cdi
- Thread starter griff104
- Start date
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How long has this been happening? If it's only a few days it could just be air settlement with the air coming out of the auto air vent on the boiler.
Check auto air vent for leaks. Check prv pipe outside for drips.
Check auto air vent for leaks. Check prv pipe outside for drips.
Thanks for the reply Dave, this has happened for over a week since the fitting of the new rad. It is not the prv pipe, as I have ckecked this numerous times and it is dry. The system now seems to have settled at 0.5 bar, if I put more water in it just loses pressure. But I will need to connect the new rad shortly to keep the house warm. How do I find out if it is the auto air vent?, or isolate the boiler to see if there is any problems with the boiler rather than leaks in the pipes.
With the outer case off visually inspect the auto air vent.
Pressurise boiler to 1.5 Bar then turn off ch isolating valves under the boiler and leave as long as possible without using the boiler.
If there is no drop in pressure then it confirms a leak in the system.
Pressurise boiler to 1.5 Bar then turn off ch isolating valves under the boiler and leave as long as possible without using the boiler.
If there is no drop in pressure then it confirms a leak in the system.
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first check that your safety outlet to the outside is not leaking. secondly check pressure in the expension vessel, lower the pressure in the system to about 0.5; vessel should be about 1 at this point. check ph and opacity
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