Compact boiler recommendation wanted

[gerryt]

I live in a small two bedroom terrace and currently have a 20 yr old Glowworm Economy 40 boiler with hot water tank and 6 radiators.

I am looking to replace this boiler with a similar sized boiler (D30, W35, H60cms) as space is at a premium.

I am looking for recommendations for compact boilers, not sure whether to go with a combi or open vent type.

I have come across the Vitodens 100-W Compact which has very similar dimensions.

Any other suggestions ?

Also my current boiler has a 15mm gas feed to it. Will a new boiler require a 22mm feed or will 15mm suffice ?

Cheers

 

[bengasman]

There are no small size boilers that are as good as full size boilers; think carefully what is the most important: more space or more reliability.

 

[D_Hailsham]

I live in a small two bedroom terrace and currently have a 20 yr old Glowworm Economy 40 boiler with hot water tank and 6 radiators.

Your heating requirement will be about 10kW. You can check this by using the Boiler Size Calculator

I am looking to replace this boiler with a similar sized boiler (D30, W35, H60cms) as space is at a premium.

I have come across the Vitodens 100-W Compact which has very similar dimensions.

D285, W375, H600mm. The smallest is 7.9-13kW

Also look at the Remeha Avanta

D290, W400, H600mm (combi are D300, H670mm). The smallest heat only is 6-12kW.

Both Viessmann and Avanta will give a 5 year warranty.

Also my current boiler has a 15mm gas feed to it. Will a new boiler require a 22mm feed or will 15mm suffice?

It will depend on the length of pipe and what other gas consuming devices you have. Just because the connection is 22mm, that does not mean that you must have 22mm pipe. Provided the pressure at the boiler is correct and the drop from meter to boiler is within limits, a 15mm pipe is ok.

If you are thinking of a combi, you need to check the incoming flow rate from the water mains. 10 litres/min will be enough if only one tap is on at a time, but if you are having a shower/bath and the washing machine is on at the same time you need 20l/min or more. The flow rate will determone the boiler size. You need 2.5kW per litre/min.

You can check the flow rate at the kitchen cold tap using a marked bucket and a watch. However many modern taps severely restrict the flow rate, so if you have garden tap, use that one instead.

 

[gerryt]

Thanks to all for the quick replies.

D_Hailsham:
The boiler is on the kitchen wall about 1.5m from floor. The gas meter is on the same floor level about 10m away. The only other gas appliance is the hob and oven.

I measured the flow rate from the garden tap and it is approx 9 litres per minute.
Will this flow rate be sufficient to run a shower off a combi boiler ?
We currently have a 9kw electric shower.

Does this new information impact on the boilers recommended i.e
Remeha Avanta and the Vitodens 100-W Compact.

Cheers

 

[MJN]

The Viessmann p****s allover the Remeha in quality mate

Can you elaborate on that?

I've got both boilers on a shortlist for an eventual upgrade so would be interested to hear your experiences as all I can really go off is glossy brochures etc.

Mathew

 

[JohnD]

I have a Viessmann 100 Compact. I chose it because it is extremely simple (not much to go wrong, especially compared with a Combi), has a stainless steel heat exchanger, and a 5-year guarantee provided it is fitted by one of their trained installers. It is also very small and quiet, but these factors were not important to me.

Despite two very cold winters, my annual gas usage has reduced from 1570 m³ to 1300m³ (I like to think it would have been lower given ordinary winters. With my old iron boiler, in the last cold winter, 1995/6, I used 1807m³ ). Keeping the HW cylinder means I get a greater flow of hot water than a combi can provide.

I am very happy with it. However as you have an existing, old, open-vented system, it is essential to have it thoroughly cleaned and powerflushed before fitting the new boiler. There is likely to be a lot of old sediment and scale inside your system. It is worth getting a Magnaclean or Spirovent to capture whatever old muck is in the system (you can never get it all out). About a month before you expect to get your new boiler, put a litre of Sentinel X400 in the system, it will start loosening the sediment and will make the cleaning easier.

 

[bengasman]

The Viessmann p****s allover the Remeha in quality mate

Can you elaborate on that?

I've got both boilers on a shortlist for an eventual upgrade so would be interested to hear your experiences as all I can really go off is glossy brochures etc.

Mathew

Far better engineering all over. Apart from that, I recently picked up a rumour ( I would not install Remeha's myself ) that they are not all that great on warrantee either

 

[JohnD]

I have been reading the Viessmann 100 review pages, and it seems to me that the dissatisfied customers are those with one or more of the following pitfalls:

- an early model of boiler
- no 5-year parts and labour warranty, as you get with an approved installer
- the new boiler was fitted on an old system which is likely to have had a lot of dirt, rust, sludge and sediment in it, and may or may not have been properly cleaned.

I had none of those, and mine has been entirely satisfactory.

 

[transam]

I have been reading the Viessmann 100 review pages, and it seems to me that the dissatisfied customers are those with one or more of the following pitfalls:

- an early model of boiler
- no 5-year parts and labour warranty, as you get with an approved installer
- the new boiler was fitted on an old system which is likely to have had a lot of dirt, rust, sludge and sediment in it, and may or may not have been properly cleaned.

I had none of those, and mine has been entirely satisfactory.

Hmm no 5 year parts & labour warranty ?? meaning that they have had to pay out for a repair after X years ??

On a different note maybe ? the amount of posts one see's about who ever has a particular boiler that hasnot gone pear shaped in 2 or 3 years ect pretty much sums up the domestic boiler market in the UK

carp in the system ??? tell the manus to **** off fit a plate exchanger on the heating , what will the manus do ??

 

[mysteryman]

I do not see how anyone who does not spell four letter words correctly expects to be taken seriously on a written forum.

Boilers do not come away from the factory full of 'carp', and neither do the boilers make 'carp' as they work. Any debris in a boiler has come in from a dirty system, or from poor installation work.

A carp is a fish that is much loved by Germans - they don't leave them inside their boilers.

 

[D_Hailsham]

The boiler is on the kitchen wall about 1.5m from floor. The gas meter is on the same floor level about 10m away. The only other gas appliance is the hob and oven.

Only the installer can tell you if you need to install a larger gas pipe. He wll measure the pressure at the meter and at the boiler. Provide it does not drop by more than 1 mb at the required flow rate, you will be not need a new pipe.

I measured the flow rate from the garden tap and it is approx 9 litres per minute. Will this flow rate be sufficient to run a shower off a combi boiler? We currently have a 9kw electric shower.

That is a very low flow rate and at the lower limit for a combi boiler. It might be worth checking if the main stop cock has been closed down, also check the water companies stopcock on the pavement. If 9l/min is the max you can get, I would not contemplate a combi.

 

[gerryt]

D-Hailsham,

thanks for the reply.

I rechecked my waterflow on the garden tap using a 10litre bucket and it filled at 45 secs. So the flow is approx 13l per minute.

Is this sufficient for a combi ?

thanks again.

 

[GaytonTonner]

With a two bedroom house go for a compact combi if the mains is up to it. You will appreciate the space gained.

 

[D_Hailsham]

I rechecked my waterflow on the garden tap using a 10litre bucket and it filled at 45 secs. So the flow is approx 13l per minute.

If you live alone, then 13l/min will be OK, but if there are more people in the house you must remember that every hot and cold outlet is supplied from the incoming cold mains: shower, bath, hand basin, toilet, washing machine, dishwasher etc. So flushing the toilet will be noticed by someone having a shower.

The Remeha 35C would be suitable.

 

[JohnD]

I have a Viessmann 100 Compact. The Compact is not a combi, it needs a hot water cylinder. It is unusually small.

If you want a combi, the Vitodens 200 is probably a better boiler.