The Manufacturers Instructions state specifically that a radiator should not be part of the by pass. [The myson fan convector is basically a radiator]
When boilers are designed they are tested in conditions as per the manufacturers instructions. If you do ANYTHING outside of these design parameters then the boiler MAY NOT work as intended. Unless you know what these design parameters are then it is unwise to detract from the instructions.
Generally speaking boiler manufacturers design a max temperature difference between the flow and return next to the boiler of 11ºC during all stages of the heating process. If the temp difference is greater than 11º the sudden increase in temp as the water passes through the boiler then the water may boil inside the heat exchanger resulting in 'kettling'.
What you have there is a substitute for a correct installation which appears to be working OK. Or is it? and if it is will it continue to do so as the system gets older and the sludge builds up or if you altered the system or perhaps if all the TRV's closed at the same time?
My advice can not be any other than to say fit the bypass as per the Manufacturers Instructions. Even if you dont need it now you may do at a later date.
When boilers are designed they are tested in conditions as per the manufacturers instructions. If you do ANYTHING outside of these design parameters then the boiler MAY NOT work as intended. Unless you know what these design parameters are then it is unwise to detract from the instructions.
Generally speaking boiler manufacturers design a max temperature difference between the flow and return next to the boiler of 11ºC during all stages of the heating process. If the temp difference is greater than 11º the sudden increase in temp as the water passes through the boiler then the water may boil inside the heat exchanger resulting in 'kettling'.
What you have there is a substitute for a correct installation which appears to be working OK. Or is it? and if it is will it continue to do so as the system gets older and the sludge builds up or if you altered the system or perhaps if all the TRV's closed at the same time?
My advice can not be any other than to say fit the bypass as per the Manufacturers Instructions. Even if you dont need it now you may do at a later date.