To combi or not combi delimna?

AMO

Hi all,

We have a 4 bed built in the 80s extended to a 5 bed house using 8mm microbore.

Our Gloworm 60,000 BTU conventional boiler that was put in when the house was built no longer works.

We have Homeserve cover and the boiler was categorised as beyond economic repair.

An independent engineer would replace the boiler with a Worcester Bosch Greenstar R30i and the cost is around £2500.

Homeserve would install a 30CDI Classic at a cost of £2800.

However, because the boiler is beyond economic repair, they use a company to provide a free boiler replacement option (Safelink I think). The main restriction to this route is that the boiler has to be an Ideal boiler (only 2 tr warranty if coming from Homeserve). But you can pay about £200 to extend to a 7 yr warranty or something.

There are 2 options here:
1) Like for like replacement - conventional boiler - £1400.
2) Combi-boiler (35Kw) - £1900.

Either way the options look attractive and money saving both in installation and running with the latter.

I have 3 concerns:
a) Its a 5 bed house (1 bathroom, 1 electric shower) - there are views that combi-boilers are not good for larger houses.
b) We have 8mm microbore - there are views that its not designed for pressurised systems.
c) Ideal boilers. People say that they're getting better, but still have problems longer term and engineers say they're good mainly because of the commission system.

Anyway, which way would you choose?

Thanks.

AMO

EmmyLou30

I'm not a heating engineer, but we went from a hot water tank/cold tank in the loft/standard boiler set up to a combi to free up the old airing cupboard space and remove a potential source of leaks in the loft (I just didn't like not being able to 'keep an eye' on it!). We have 8mm micrbore pipework and replaced all the old scruffy rads with new ones and new valves. We have a standard shower in the en suite off the boiler, as well as a bathroom - the argument for not having a combi is generally that supplying 2 sources of hot water in a multi bathroom house at once is too much for it. Well ours copes just fine on the rare occasion we use both together. If you have an electric shower it's less of an issue to have a combi I would think.

Alex1983

A big combi will be fine if your only have 1 bathroom.

8mm pipework isnt ideal but as long as the pipework is clean it will be fine.

I would do everything I could to avoid ideal, poor quality, cheap boilers with terrible aftercare.

You will get all different answer on best manufacturer based on peoples previous experience etc. I would personally go with Vaillant, long history of very reliable boilers and decent customer service if required.

AMO

Alex1983 wrote: »

A big combi will be fine if your only have 1 bathroom.

8mm pipework isnt ideal but as long as the pipework is clean it will be fine.

I would do everything I could to avoid ideal, poor quality, cheap boilers with terrible aftercare.

You will get all different answer on best manufacturer based on peoples previous experience etc. I would personally go with Vaillant, long history of very reliable boilers and decent customer service if required.

Thanks. Unfortunately to go the combi-route I have to go with this company to get the boiler and installation cheap and the terms specified are that it has to be an Ideal boiler. Its a great offer as they get rid of the water tanks etc but the Ideal boiler is just....not ideal!

It might be a case of - go for it because its such a good price and try to lengthen the warranty with Ideal. Then if you need to replace the combi, its just a change of boiler thereafter.

J_B

Alex1983 wrote: »

A big combi will be fine if your only have 1 bathroom.

That was my first thought, but 5 bedrooms and only one bathroom???

Looking to the future, to add value maybe another bathroom or two and then the combi *may* not be sufficient???

Bill23h

AMO wrote: »

Thanks. Unfortunately to go the combi-route I have to go with this company to get the boiler and installation cheap and the terms specified are that it has to be an Ideal boiler. Its a great offer as they get rid of the water tanks etc but the Ideal boiler is just....not ideal!

If you can afford it, paying now for a decently sized Worcester Bosch Combi will probably save you money in the long run. A registered installer will give you a full 7 year warranty which means you can scrap any maintenance contracts you have. We scrapped an old Potterton which was the house builders original from 1990 and cut gas consumption by half. That, combined with not paying out anything to british Gas for a service contract will almost pay for itself over the 7 years. WB are ultra-reliable and super-efficient. I wouldn't have anything else, though I 've heard Vaillant run them close. We got a WB 42i for a house of similar age and size to yours, and it's more than adequate water-wise.

bris

Combi boilers are not good for multiple bathrooms, the size of the house is irrelevant. A 3 bed house with 1 bathroom and 2 ensuits would struggle with a combi.


Your 5 bed house will be fine with a combi, the 1 bathroom will suit it just fine.


Ideal boilers aren't bad and getting a better warranty for a couple on hundred quid is a no brainer. Don't fall for this nonsense that Worcester Bosch are the best, 20 years ago yes, but now they are just one of the pack.

MikeEngTech

Hi,
I!!!8217;m a heating engineer. Member of the Chartered institute of Plumbing and Heating Engineering as well. The people you have in should be able to answer these questions. Ask them why they have recommended what they have and tell them your concerns.
Many plumbers/heating engineers quoting for combi boilers in larger properties seem to forget about the delay in hot water. In Germany they say a combi boiler is only suited for up to 7m of hot pipework. Personally I think up to around 10-12M max. Otherwise either move the combi more centrally or just upgrade the cylinder and you could even run a domestic hot water circulation loop to reduce the delay and wasteage of water waiting for the hot water to reach the taps.
Seal the system. If old pipes leak under a bit more pressure then you need new pipes. Sealed systems will always me more efficient and almost always more reliable in the long run in my opinion. You shouldn!!!8217;t even need inhibitor then if your fill water is good.
Powerflush if needed is great but expect to pay more for a proper flush.
Filters are probably worth paying extra for.
8mm pipe shouldn!!!8217;t make a difference but if the manifolds are small or the branches too long and the system is dirty then the been boiler may struggle. Nothing a good flush shouldn!!!8217;t be able to sort. If there is issues with the pipe sizing in the property then a new boiler won!!!8217;t sort that.
Finally if someone offers !!!8220;modulating controls!!!8221; such as OpenTherm or weather compensation then you should probably go with them. All this on/off stuff is very old now but still the most common and dont make the most of condensing efficiency.
You can PM me if you like to see if I know someone in your area.
Regards

jhe

I have a Worcester Bosch 38cdi classic that replaced a previous Worcester Bosch last year.
I got it installed by a Worcester accredited installer and also got a Worcester thermostat as long as I get it serviced every year I get a 10 year parts and labour guarantee

AMO

Slight dilemna - Homeserve, Help-Link and Ideal all deny that the Logic boler warranty can be extended. With Ideal, you need to change to another boiler Logic+, but Homeserve and Help-Link won't allow that.

Possibly any warranty extension is provided by Homeserve, but no-one knows anything.

Furthermore, it may be in their interest to keep you subscribed to their heating insurance.

Reviews on Logic boilers might be only positive for Logic+ and higher ranges but not the lowest Logic range? Anyone with any views?

Thanks.

Alex1983

They are terrible boilers, but will keep me busy for a long time so I shouldnt moan. I really wouldnt let them fit a logic in my house. I realise its a cheap price but theres a saying pay cheap pay twice, whats actually wrong with your boiler and what model do you have. I see this often that Homeserve say its uneconomical to repair, is that in there terms and conditions or do they just decide its uneconomical.