Combi, Megaflow or Cylinder - CONFUSED!

Shaanbles

I am replacing and moving my current Baxi combi boiler - the boiler works fine but is probably over 8 years old and as I want to move it out of the kitchen and into the garage I figured I should get a new boiler.

Water pressure is very high - 4 bars and the water flow is also very high. (only one of the plumbers tested this)

I have a 3 bedroom house, one bathroom and there's only myself and my little girl.

I am VERY confused as to what type and what make of boiler to go for; had 3 quotes and they've each said something different but then said it's up to me!

If I got a cylinder would it mean I spend more on gas bills as hot water would just sit in the tank waiting to be used?

What is a megaflow? Does it still have a tank? How does it differ from the cylinder type?

I had mentally decided on a Viessman 100 combi but now I don't know :undecided

Someone has now just mentioned a condensing boiler to me - arghh, even more confused!

All advice greatly appreciated.

TIA
Shaanbles

gas4you

Forget about getting a standard hot water cylinder fitted. With the tank in the loft and all the extra new pipe work, it is a very expensive option, old fashioned and unnecessary.

A Megaflo ia an unvented mains pressure cylinder. Megaflo is just a brand name made by Heatrae. Many other makes are available but megaflo are generally accepted as the best. However, Santon and Mian are also the same cylinder, out of the same factory, but have an external pressure vessel and are a lot cheaper, especially the Main, but come with less warranty.

Unvented cylinder option will be expensive compared to a new combi, but will give the best hot water flow.

A new combi will be the easiest and cheapest option, and with only the 2 of you I suspect that needing more than one hot outlet running at the same time is not a priority?

Also, has your current Baxi provided you will enough hot water in the past? If so then this may be all you need now.

All boilers today will be condensing, whether they are a combi or standard boiler.

Personally I would think you would be best to stick with a combi, maybe getting a more powerful one fitted if you want faster filling baths or more powerful showers, eg a 35Kw or 39Kw.

Veissmann have a good name and many like them, I'm not one of them at present. I believ they come with a 5 year warranty if fitted by an installer who has attended their training course.

If you had set your mind on this, then go with it, or another make such as Broag or ATAG. The ATAG A325EC combi is about the best on the market at present.

Don't be persuaded away from what you want.

C_Mababejive

I would hope my boiler lasts more than 8 years !

My current one is 25 years old.

Aside from that, a new combi is the least expensive option if you can put up with the water output.

Dont assume that cylinder full of hot water=inefficiency and waste as combis can be much more wasteful of expensive and natural resources.

Canucklehead

Shaanbles wrote: »

I am replacing and moving my current Baxi combi boiler - the boiler works fine but is probably over 8 years old and as I want to move it out of the kitchen and into the garage I figured I should get a new boiler.

Water pressure is very high - 4 bars and the water flow is also very high. (only one of the plumbers tested this)

I have a 3 bedroom house, one bathroom and there's only myself and my little girl.

I am VERY confused as to what type and what make of boiler to go for; had 3 quotes and they've each said something different but then said it's up to me!

If I got a cylinder would it mean I spend more on gas bills as hot water would just sit in the tank waiting to be used?

What is a megaflow? Does it still have a tank? How does it differ from the cylinder type?

I had mentally decided on a Viessman 100 combi but now I don't know :undecided

Someone has now just mentioned a condensing boiler to me - arghh, even more confused!

All advice greatly appreciated.

TIA
Shaanbles

Good morning: a combi would suit your needs. Some RGIs can offer the Viessmann Vitodens 100 combi and the Remeha Avanta Plus (aka Broag) with a 5 year parts and labour warranty subject to annual servicing and installation following the manufacturer's specifications. More on your options here.

HTH

Canucklehead

Shaanbles

gas4you wrote: »

Unvented cylinder option will be expensive compared to a new combi, but will give the best hot water flow.

A new combi will be the easiest and cheapest option, and with only the 2 of you I suspect that needing more than one hot outlet running at the same time is not a priority?

Also, has your current Baxi provided you will enough hot water in the past? If so then this may be all you need now.

All boilers today will be condensing, whether they are a combi or standard boiler.

Personally I would think you would be best to stick with a combi, maybe getting a more powerful one fitted if you want faster filling baths or more powerful showers, eg a 35Kw or 39Kw.

Veissmann have a good name and many like them, I'm not one of them at present. I believ they come with a 5 year warranty if fitted by an installer who has attended their training course.

If you had set your mind on this, then go with it, or another make such as Broag or ATAG. The ATAG A325EC combi is about the best on the market at present.

Don't be persuaded away from what you want.

Thank you for your responses.

Yes the Baxi has given me just about enough hot water; although sometimes it doesn't always supply enough for a really hot bath.

Out of interest how much more would an unvented option cost over a combi? If it's not a huge amount then it maybe worth it.

Also what would be your top 3 reasonably priced combis and top 3 unvented boilers? The plumber I will probably go with has said Baxi actually came top in a recent survey - but reading on here and other sites Baxi isn't rated that high. I've not heard of ATAG but will research it.

Shaanbles

Shaanbles

C_Mababejive wrote: »

I would hope my boiler lasts more than 8 years !

My current one is 25 years old.

Aside from that, a new combi is the least expensive option if you can put up with the water output.

Dont assume that cylinder full of hot water=inefficiency and waste as combis can be much more wasteful of expensive and natural resources.

I'm only replacing the Baxi as I actually want to move it into the garage - I agree I boilers should last for many more years than 8! It just seems cost effective to put a new energy efficient one rather than keep this one.

So are you saying combis use more energy than cylinder boilers? Now you know why I'm so confused!!

gas4you

Combi's need and use a greater volume of gas when they come on for hot water, but are still over all, more efficient due to only heating the water you will actually use.

If your current Baxi is 24Kw or 28Kw, then look at having a 35Kw or bigger combi fitted.

bengasman

Viessmann 100 combi would be an excellent choice for your situation. It will provide all you need, and is an fantastic bit of kit.

Make sure you get it installed by a Viessmann approved installer, and you will get 5 years full warrantee on parts and labour.

Another thing to check, is that the old cylinder and tanks are removed, and all the taps in the house converted to mains. The old tank and cylinder system is disgusting, and form incredibly good breading places for bacteria.

Pincher

Shaanbles wrote: »

I'm only replacing the Baxi as I actually want to move it into the garage - I agree I boilers should last for many more years than 8! It just seems cost effective to put a new energy efficient one rather than keep this one.

Legislation requires all new domestic installs be condensing boilers, so your Gas Safe registered engineer may refuse to install the old Baxi, assuming the Baxi is a non-condensing combi.

Shaanbles wrote: »

Yes the Baxi has given me just about enough hot water; although sometimes it doesn't always supply enough for a really hot bath.

The Baxi should have a sticker label with Model No.
Give us the input and output kW (could be in BTU).

Shaanbles wrote: »

Out of interest how much more would an unvented option cost over a combi? If it's not a huge amount then it maybe worth it.

For one bathroom, a cylinder is a waste of space, unless you want solar thermal, wich you may want if the RHI goes live in April 2011.
Otherwise, combi is the simplest solution.

It takes a few seconds for the heat exchanger to get hot, so you are wasting water every time you turn on the hot water tap with a regular combi. There are combis with a small hot water tank built-in, which the system keeps hot. This means when you turn the kitchen tap, hot water comes quicker. There are wallmounted ones with smaller tanks, and floor standing ones with bigger tanks.
You don't need a big tank for one bathroom, because the combi kicks in when you draw hot water.


Wall mounted

Vaillant EcoTEC Plus 937 HE Power Store Combi Storage Boiler

"An good example of the size of property this boiler would suit is a 3 to 4 bedroom house with one bathroom and an ensuite.
The Vaillant ecoTEC Plus 937 HE Power Store achieves this performance with a 15 litre water store and 1 litre expansion vessel fitted in to the boiler casing."


Potterton Promax HE 150i Floor Standing Storage Boiler c-w Cylinder Features:

• Fully modulating outputs from 6.8kW to 24kW
• 90L 115L or 150L capacity
• SEDBUK Band A

"The Potterton Promax Floor Standing Storage Boiler has integrated hot water storage facility and is central heating boiler combined. The Potterton Promax HE Floor Standing Storage Boilers operate on a hot water priority system."

Just for illustration, there are too many models out there.

By the way, "hot water priority" means there's not much heat going to the central heating when you are running the shower. You can have a separate gas water heater, and a boiler (not combi) dedicated to central heating only. This allows you to use a smaller capacity GCH boiler, so it has more chance to enter condensing mode, improving efficiency. Both can be wall mounted.

Shaanbles wrote: »

Also what would be your top 3 reasonably priced combis and top 3 unvented boilers? The plumber I will probably go with has said Baxi actually came top in a recent survey - but reading on here and other sites Baxi isn't rated that high. I've not heard of ATAG but will research it.

Check out prices here:

http://www.plumbnation.co.uk/site/boilers/

They don't have all the brands mentioned here, but has a good range, and pretty good information.

I am partial to Potterton, which is part of the Baxi group. They have a very good After sales support called HeatTeam.

Atagt stuff are designer chic, with price to match, it's wasted in a garage.

Shaanbles

gas4you wrote: »

Combi's need and use a greater volume of gas when they come on for hot water, but are still over all, more efficient due to only heating the water you will actually use.

If your current Baxi is 24Kw or 28Kw, then look at having a 35Kw or bigger combi fitted.

Current one is a Baxi combi 105e - not sure about the output

gas4you

Thats a 28Kw combi.

Check your cold mains flow rate and pressure and look at going for a 35Kw or greater if the cold flow allows it.

Top of the bunch is the ATAG A325EC, then look at the Broag Avanta Plus 35c or 39C.

ATAG are not much different in price to other makes thses days.