Opinion on Plastic Central Heating Pipes

[alba2]

I would be interested in opinion of a c.h. system with 10mm plastic Hep2O class S pipes, because we have just bought a new property with that system

The main reason I ask is because approximately 20 years ago we bought a property with plastic c.h. pipes and we had a lot of bother. Despite having a barrier the pipes managed to let O2 into the system and our pipes and radiators got gunged up within a couple of years. We had repeated pump failures etc. By year 10 it was quite bad. Whole lengths of vertical pipe were blocked and had to be cut out and replaced.

Are the newer plastic pipes better?

What would the longevity of such a system be? I ask because we have a mix of wood and tiled floors! It would prove expensive to lift and replace.

Does a good dose of inhibitor help? We have a Viessmann boiler and I think they don't advise inhibitor in their system.

Due to those previous problems I had a c.h. engineer retro fit a Spirotech filter. Will this prolong the life of the system and make it more trouble free?

 

[Madrab]

Are the newer plastic pipes better? -
Yes - better engineered barrier pipe these days

What would the longevity of such a system be? I ask because we have a mix of wood and tiled floors! It would prove expensive to lift and replace. -
If fitted and commissioned correctly then it will last as long as most other materials

Does a good dose of inhibitor help? We have a Viessmann boiler and I think they don't advise inhibitor in their system. -
Cant say I've heard that they especially state no inhibitor, inhibitor is a coverall protection and is recommended IMO

Due to those previous problems I had a c.h. engineer retro fit a Spirotech filter. Will this prolong the life of the system and make it more trouble free? -
A spirotech filter will remove solids/magnetite material circulating within the system and should prolong the systems life. Make sure it's cleaned/bled once every few months initially until it starts to run clear, then once a year.

 

[jeff the gasman]

A lot of the older systems used cheap stainless steel inserts that attracted magnetite. If the new inserts are plastic BINGO.
NO PROBLEMS.
Jeff.

 

[alba2]

Thanks to both of you. That has made me feel better about plastic pipes.

As a supplementary. The Viessmann boiler has been losing pressure. It loses 1 bar every 2 weeks. It is only 4 months old and it just had the heat exchanger, pump and pressure sensor replaced. This was due to it also overheating and cutting out when the domestic water side was on high demand. Probably trial and error. This did not fix the problem and we are waiting for a Viessmann engineer to visit. It is an F1 fault.

I am concerned that it could be a slow leak from the plastic piping. If there is a leak it has not yet been noticed in the flat below. Could this leak be appropriately sealed with a liquid leak fix? Does this cause any problems for the boiler etc? We have new real wood floors and I don't really want to lift them.

The only other thing I can think of is the pressure release valve. As it is a new system this connects via the condensate pipe into the internal plumbing system. It is not accessible. The condensate pipe was detached at the boiler and there was no steady drip.

PS the inserts look like stainless steel.