can a combi boiler run as a vented system ?

[jim007]

I may be missing something simple here but so far no one has given me a reason for not being able to do this.
can a combi boiler heating side be converted from a sealed system to a vented system by fitting an expansion tank and replacing the heating side pressure switch with a float switch in the tank.

For those who wish to know the reason for this is a wood burning stove with back boiler.

Using a thermal store and the pipework involved is not practical and lack of space.

thanks

Jim

 

[jim007]

so guessing no one can answer this

 

[kevplumb]

depends on the combi make and model so unless you tell us

as the communual crystal ball is in for a service due to the milage it has done by twits that think everybody is phycic

 

[baxpoti]

can a combi boiler heating side be converted from a sealed system to a vented system by fitting an expansion tank

Have seen this done, you'll need a good head of water 5m+
Check with the combi boiler manufacturer as to whether warranties are valid etc.

 

[Balenza]

I may be missing something simple here but so far no one has given me a reason for not being able to do this.
can a combi boiler heating side be converted from a sealed system to a vented system by fitting an expansion tank and replacing the heating side pressure switch with a float switch in the tank.

For those who wish to know the reason for this is a wood burning stove with back boiler.

Using a thermal store and the pipework involved is not practical and lack of space.

thanks

Jim

The first priorty with solid fuel is a storage capability for the dhw.
You can achieve this via a twin coil vented cylinder or a thermal store and it is also possible with a twin coil/phe charged UV cylinder if you know what you are doing.

Their will be many times when the combi will have the heating system up to temperature and your woodburning stove then over heats the space temperature further.

When DHW is required the combi is then the only means of providing this whilst the stove over heats the rads.

 

[simond]

If you are fitting an oil combi, the current Worcester Bosch range can be open vented for the rads.

 

[Agile]

Its usually better to keep the combi system sealed and add an open system for the wood stove and a heat exchanger to transfer the heat.

A heat sink rad is needed on the wood side.

Tony