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Central Heating

Vaillant EcoTec 638 reaching max pressure 3.1 on radiator circuit

Anonymous user 23/02/2024 - 3.37 PM

Hiya - Something has happened to my boiler, 2 year old, service March 2020, the boiler is packing up 15mins into the heating run in that it is cutting out the flame and waiting for pressure to drop back down from max 3.1. It is then stuck in the loop. There is no air in my radiators, also no air in the magna clean. I have 3 by-pass valves, 1) radiator circuit 2) UFH circuit 3) hot water. The rads heat up fine suggesting valve is opening. So far, my hot water and UFH circuits are not affected, it is only the radiator circuit that is showing this problem... I have also noticed boiler is not able to reach its target max temperature 75, it is maxing out at 70 for UFH and radiator circuit, Is this air inside boiler mechanics or expanssion vassel ? What could fail expansion vessel ?

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3 Answers

Anonymous user

has the expansion vessel failed. basically they are like a car tyre with an air pressure inside them, once your heating system warms up the water expands, compressing the air in the vessel to accomodate the increase in volume of water. failed vessel would give this increase on your water pressure reading to check, lower the water pressure in the heating system, disconnect it from the system, look for the air valve top up point on it (same as a car tyre) depress it or check with a pressure guage to see has it pressure or not, or if it leaks water from this point it needs replacing check that the vessel installed is properly sized for the system ie water expands by about 10% so if there was 100litre of water in your entire heating system the vessel would want to be 10litre minimum
Answered7 December 2020
5

D & R Property and Plumbing Maintenance

Rating: 4.9 out of 5
New Romney
expansion vessel membrane has failed. sludge ,over pressure, they fail all the time.
Answered7 December 2020
1

Trevor Messenger Plumbing and Heating

Rating: 4.9 out of 5
Castle Cary
Would check expansion vessel, should be pumped up to 3 bar
Answered6 December 2020
1