Boilers - pressurised or not

[djchapple]

I am seeking a quote to replace a 20 year old boiler. The system is a good old fashioned vented system with gas boiler with hot water and rads.

I have been quoted for a vented system and one where the boiler loop is pressurised. (Glowworm 18hxi and 18sxi)

What are the pros and cons re pressurised and vented systems and are Glowworm boilers with stainless steel heat exchangers any good?

 

[croydoncorgi]

The ONLY boilers that are any good are ones with heat exchangers that don't corrode. Stainless steel is a good start!

The advantage of a pressurised system is that there is very little chance of air getting into the system, so no dissolved oxygen, so no corrosion in radiators. Some open-vented systems stagger on with minor leak(s) for years but it's essentially up to you! If you try to create a sealed system out of crepe pipework and fittings with leaks, you may have a torrid time getting it water-tight. If you don't get it tight, you will have a miserable time re-pressurising it frequently and dealing with other consequences. Get it fixed up properly and checked out once a year and topped up with inhibitor, and it should last 'indefinitely'. Your choice.

 

[gas4you]

Pay a bit more and go for a better make with a proper 2 year warranty.

The HXi is the discontinued Vaillant Ecomax pro but with less diagnostics on board.

 

[Dan Robinson]

Pressurising the heating system is better in the long run, but will expose weak rads, pipes, valves and joints.

Whether or not this is a problem depends on the state of your heating system.

Certainly choose a better boiler than a Glow worm - there's tonnes of advice here.

 

[JB Gas]

seal the system fit new raad valves and a wb 18ri