EUROCOMBI SX 20 MFFICE with sealed combustion chamber type c?

If you have water dripping from the 15mm blow off pipe outside there are a number of possible causes.
1. The expansion vessel inside the boiler has either lost its charge of air or it's membrane is split, so you possibly need a new expansion vessel. Depending on how the boiler has been sited will depend on whether the boiler needs to be taken off the wall to replace this part.
2. The pressure relief valve could be worn allowing water to pass to outside and causing pressure loss to the system.
3. The filling loop could be passing.

First thing to do is to ensure that the boiler pressure is set to 1.5 bar when cold. Turn on the heating and watch the pressure guage. If it rapidly rises up towards 3 bar then the expansion vessel is definately at fault.

Gas Technical Services
July 2008

If you have water dripping from the 15mm blow off pipe outside there are a number of possible causes.
1. The expansion vessel inside the boiler has either lost its charge of air or it's membrane is split, so you possibly need a new expansion vessel. Depending on how the boiler has been sited will depend on whether the boiler needs to be taken off the wall to replace this part.
2. The pressure relief valve could be worn allowing water to pass to outside and causing pressure loss to the system.
3. The filling loop could be passing.

First thing to do is to ensure that the boiler pressure is set to 1.5 bar when cold. Turn on the heating and watch the pressure guage. If it rapidly rises up towards 3 bar then the expansion vessel is definately at fault.

Gas Technical Services
July 2008