COMBI BOILERS AND GAS SUPPLY

[geeveepee]

Back in 2004 on this forum (and in other places) no-one seemed to have a good word for combi boilers - except as a never ending source of repair work.
Have opinions changed? Has reliability improved sufficient to make them worthy of consideration?
We have a 35yr old microbore system which is currently on its 2nd boiler which needs replacing. The gas supply is 15mm and we have been told that we will have to have a new 20mm supply, is this correct? And if so will it have to be run around the outside of the house as the gas meter is at one side of the house and the boiler at the other. Aesthetically not very appealing.
PS thanks for previous advice

 

[ChrisR]

Yes they're better. Not fab, but better.
More likely 28mm needed.
If your rads are 35 years old, it might well be worth changing them all - not all that expensive.

Microbore is OK if it's in good condition and well designed.

 

[superdupergasman]

nothing wrong with combi's as long as you get a good brand, worcester, vaillant, viessmann and its well installed and the system flushed, inhibited.

Gas pipe upgrade is a must!!!

I had a 35kw boiler on a 15mm supply last week was only giving a 11mb working pressure when you are ment to have 20mb so performance was seriously affected.

Worcester say in manf instructions that on no account should any less than 22mm gas supply be used to most of their boilers.

If you get into serious high output combi's then 28mm supply may be needed.

Whats wrong with running pipe under floor from front of house to rear??

 

[Agile]

nothing wrong with combi's as long as you get a good brand, worcester, vaillant, viessmann and its well installed and the system flushed, inhibited.

Nothing wrong with any combi as long as its only fitted on a clean system. 95% of all the combi boiler faults I go to are as a result of dirty water!

Tony