Regular boiler replaced with Bosch 25i system

[David B]

Quick question - our old regular boiler was just replaced after it failed. They installed a new Bosch 25i system boiler instead. I don’t really understand the details, but they say they fed it from the attic tank and so I should ignore the fact the pressure gauge is at 0. I think it is designed to be connected to mains water. It seems to be working fine - is this an acceptable setup or will it affect warranty, running costs or wear and tear? Any risks with this setup e.g. leaks? Thank you very much for any advice.

 

[EvilDrPorkChop]

It should be fed from the mains using a filling loop. The small feed and expansion tank should have been removed and the system converted to a sealed system rather than open vent. Some pictures might help us.

 

[David B]

It should be fed from the mains using a filling loop. The small feed and expansion tank should have been removed and the system converted to a sealed system rather than open vent. Some pictures might help us.

Thank you for taking the time to answer!

I will try to get some photos, but essentially nothing in the house was changed and I was told they made the new boiler work by using the existing attic tank and some type of loop - so I should ignore the pressure gauge as not relevant to me. Mention of keeping cost lower.

From my reading, I would have thought yes that usually one would change to a sealed setup with a new system boiler or else why not just replace with a "regular" boiler. I wondered if maybe it was just that they had that one in stock or maybe in the industry nobody installs regular boilers any more? There was mention of "you could convert it in the future".

Overall I have no issue as it is working perfectly, but I just wanted advice on whether there are any longer term downsides to this arrangement!

 

[John.g]

Does the pressure gauge rise a little when the system heats up?, it may read ~ 0.4bar cold and 0.8 to 1bar when hot. If so, then you have a semi sealed system with a non return valve in the cold fill and a internal expansion vessel in the boiler.

 

[gmartine]

A sealed system is more efficient and oxygen ingress via the original F/E tank can also reduce the life of your system. Sounds like a lazy arse unless either cost was absolutely paramount or there may have been issues pressurising the system which unless it is absolutely ancient there shouldn't be. Pictures before judgement though.

 

[David B]

Does the pressure gauge rise a little when the system heats up?, it may read ~ 0.4bar cold and 0.8 to 1bar when hot. If so, then you have a semi sealed system with a non return valve in the cold fill and a internal expansion vessel in the boiler.

Thanks - I have noticed that sometimes the Hague is up slightly when off and is at 0 when running - though only in for a few days.

 

[David B]

A sealed system is more efficient and oxygen ingress via the original F/E tank can also reduce the life of your system. Sounds like a lazy arse unless either cost was absolutely paramount or there may have been issues pressurising the system which unless it is absolutely ancient there shouldn't be. Pictures before judgement though.

Hi cost wasn’t an issue for me but he had quoted a set price so maybe didn’t expect what he found when he opened the the system.
As I say, I don’t really mind once it’s not a totally crazy or unsafe setup. I assume just part of the boiler is being bypassed or something. I’m just not sure why they wouldn’t have put in like for a like heat only boiler? It is great to have heat again!

 

[EvilDrPorkChop]

Sounds like a bodge to me, also I'd be interest to see what Worcester would have to say from any warranty points. A system boiler is designed to run at pressures of 1 bar etc.

 

[ShaunCorbs]

It’s fine being used as a open vent boiler do no harm with an expansion vessel inside

 

[John.g]

Worcester seem or used to put a R or S in front of the "I" to show a regulsr or system boiler. (and C for combi)

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[David B]

Thanks so much to everybody for your insight and taking the time to answer.

It is just a bit annoying as some panels were removed to make this one fit, and if a like-for-like regular boiler was just done instead, it would probably have fit without the need now to redo some joinery. Also it seems illogical to install a system boiler and not set up as such. There is no ancient plumbing issue that would be a concern re: pressure.

I have queried the warranty with them.

I guess they had stock of the Bosch one that they installed, and decided to make it to work one way or the other. (They had photos of the one previously installed before they arrived).

Anyway, having the heating working again is great!

One last question - is it worth my while at some stage asking l somebody to switch it to a sealed system?

Merry Christmas all!

 

[John.g]

If designed as a system boiler I would say yes but beware in case the low pressure boiler trip has been shorted out ,if converted, then if a serious leak develops the boiler may run out of water and be seriously damaged if the boiler stats don't trip it.
Have you a link to your exact model because I read on here I think where some boilers can "officially" be run in either mode, when run in low pressure mode the digital pressure gauge is set automatically to 0?.

 

[ShaunCorbs]

If designed as a system boiler I would say yes but beware in case the low pressure boiler trip has been shorted out ,if converted, then if a serious leak develops the boiler may run out of water and be seriously damaged if the boiler stats don't trip it.
Have you a link to your exact model because I read on here I think where some boilers can "officially" be run in either mode, when run in low pressure mode the digital pressure gauge is set automatically to 0?.

Worcester’s don’t have a lwps main overheat / ntc in the hex