Heat only or system boiler?

[Mottie]

Im thinking of changing my aging boiler as I’m pretty sure I won’t see another winter out of it. Currently it’s a 26 year old heat only boiler. Just over a year ago I had the whole system upgraded (excluding boiler). It was converted to a sealed system and the controller, room thermostat and diverter valves were replaced too. I had a power flush and I had an unvented hot water cylinder fitted. The pump was replaced by myself about 2 years ago and I replaced 3 radiators so as far as I’m concerned, it’s all in good nick apart from the boiler. My thinking was that when the boiler goes, it’s just a heat only boiler that needs replacing (plus if course a mag filter and condensate drain).

If I get a system boiler, it will include a new pump, pressure valve and expansion tank but I’m thinking just replace boilers like for like as apart from the fact that those parts which I have already are relatively new and anyway, those components are external to the boiler and can be bought cheaper/quicker/anywhere whereas with a system boiler you will need to fit the boiler manufacturer specific parts. Is that thinking correct?

 

[oldbuffer]

Correct thinking. Maximum flexibility and minimum complexity.

Just make sure any new heat only boiler will be OK on a sealed system. I can't think of one that won't, but I'd draw up a shortlist of, say, 3 boilers, and check the installation instructions for each on-line to make sure it is suitable for a sealed system.

 

[oldbuffer]

Couple of other points:

1. Make sure your expansion vessel is big enough. (Depends on system size, not boiler, so if OK now, probably OK with the new).
2. Make sure there is an automatic bypass fitted. After the pump, before the zone valves, and with enough pipework (minimum 1 metre, preferably 2 or 3 metres) between bypass and boiler.

 

[oilhead]

I would rely on your existing equipment. The chances are your expansion vessel will last longer than any 'mickey mouse' unit fitted into a boiler, and when it does need replacing, the job will be easier.

 

[Mottie]

Couple of other points:

1. Make sure your expansion vessel is big enough. (Depends on system size, not boiler, so if OK now, probably OK with the new).
2. Make sure there is an automatic bypass fitted. After the pump, before the zone valves, and with enough pipework (minimum 1 metre, preferably 2 or 3 metres) between bypass and boiler.

Thanks. Yeah, the current vessel has been okay since it was fitted just over a year ago. Boiler is in loft, automatic bypass is fitted in the airing cupboard downstairs between the pump and zone valves so at least 6 metres back to the boiler.

 

[DaveHerns]

So it won't be an Intergas after what you've posted in the GD forum!

 

[Mottie]

I’d like to get in my mind a list of possible contenders and see whether any of them are recommended when I eventually get installers round to give quotes. No matter which I pick, they’ll be someone on here that will give me horror stories about that particular make/model. Just like cars - pick any car that someone rates very highly, then go on any forum and it’ll be the worse car someone has ever had the misfortune to own!

 

[DaveHerns]

Do you not think any boiler is only as good as the installer? A 5hite boiler may be good if well installed and vice versa.

 

[Mottie]

That may be try about designing a heating system Dave, but the system I have is fine. I’m only wanting a basic boiler replaced to heat the water. It’s basically connecting the flow and return plus the gas feed, flue and electrics. They’re not designing and configuring individual components inside the boiler themselves.