Unvented cylinder and boiler

[ianbunday]

Could anyone please tell me which boiler and unvented cylinder they would recommend for my house (4 beds, 3 baths). A Vaillant 637 Ecotec plus system boiler and a Range Tribune 300l cylinder have been put forward. Also - would the cylinder be a direct or indirect one (I'm not fitting them myself needless to say!) Would the 37kW be powerful enough?

Our biggest priority is showering - we like very powerful showers.

Thanks for your help

 

[htgeng]

Could anyone please tell me which boiler and unvented cylinder they would recommend for my house (4 beds, 3 baths). A Vaillant 637 Ecotec plus system boiler and a Range Tribune 300l cylinder have been put forward. Also - would the cylinder be a direct or indirect one (I'm not fitting them myself needless to say!) Would the 37kW be powerful enough?

Our biggest priority is showering - we like very powerful showers.

Thanks for your help

The boiler choice is more down to what your installer is recommending as everyone has their favourite. Personally, I would go Atag or Viessmann and you will get 10 other opinions here.

For unvented cylinder I think best value on market atm is Santon. Its a 'value' version of the Megaflo but still retaining the important features. 25 year warranty and very low position high recovery coil. If you are going for that size cylinder you may as well specify the twin coil version for a few hundred extra which will give you an easy upgrade to solar.

 

[gas4you]

Firstly I would doubt a four bed house would need a 637 unless it is a massive four bed.

I would recomend the Vaillant boiler but would say get the Vaillant unistor cylinder to go with it, probably the 210 or 260 litre in your case.

You then need a VR65 control center which lets the boiler, cylinder and Vaillant programmer/room stat all talk to each other to give maximum efficiency and control. The cylinder would also benefit from a VR10 ntc ed and the normal cylinder stat removed.

As far as I am aware the cheaper Santon only comes with a 10 year warranty, with the 25 year warranty being for the Megaflo only.

The Unistor has a 25 year warranty and a seperate expansion vessel which in my book makes it superior to the megaflo.

 

[Agile]

Normally an 18 kW would be quite adequate if the house is reasonably well insulated.

At most 24 kW.

Its a stupid misconception that the more powerful the better!

The more its oversized the less efficient because it cannot modulate down to the actual heat demand. Boilers only modulate to 3:1

Tony

 

[sanj.varah]

I can rrecommend the viessmann. I've got a vitodens 300 weather comp and Vitocell 300

What agile says is correct, you want a correctly sized boiler. However most people design the heating for a steady state, when I did mine I did it for a transient state and oversized the radiators by quite a lot.

This allows a drop in flow temperature which is more efficient. Also results in less modulation.

For a house as big as yours, with the rating of the coil which is probably around 10kW. I would have thought 30kW minimum.

 

[siwann1]

i agree with the others as to boiler sizing. i fit un-vented units atleast 3 days a week and i don't like 'range'. fit an ariston (yes, you heard right!), vaillant or megaflow. but if you fit a cylinder at this stage on a 25 yr guarentee then buy one that has 2 heating coils so that you can add a solar package to it at a later date without having to rip it out. best bet is to keep the vaillant and get their cylinder and have the option of upgrading later without too much fuss.

 

[htgeng]

As far as I am aware the cheaper Santon only comes with a 10 year warranty, with the 25 year warranty being for the Megaflo only.

http://www.santon.co.uk/santon/santon.nsf/ProductLookup/PremierPlusSolar?OpenDocument
On the features list it states 25 year warranty.

Things I don't like about the santon. The T&PR is on one side and flow/return is on the other side. This can make it awkward for installation if you are tight for space. I think the Vaillant that G4Y mentions has all the connections in a line down the middle. Much neater.

Does the vaillant have an immersion backup?

 

[bengasman]

If you are not installing it yourself, as you should not, I recommend you find yourself a good installer and follow his advice. Personally, I do an about turn when someone tells me what to do based on somebody else’s opinion. At the end of the day, if I would do what you tell me and it goes wrong somehow, would you say: okay, never mind? Chances are you would want the installer to fix the problem. the answer to the size of the boiler is simple, the rgi will calculate after a visit what your needs are.

 

[sanj.varah]

If you are not installing it yourself, as you should not, I recommend you find yourself a good installer and follow his advice. Personally, I do an about turn when someone tells me what to do based on somebody else’s opinion. At the end of the day, if I would do what you tell me and it goes wrong somehow, would you say: okay, never mind? Chances are you would want the installer to fix the problem. the answer to the size of the boiler is simple, the rgi will calculate after a visit what your needs are.

I think the problem is that most plumbers are used to fitting a particular type of boiler so they prefer to fit it, which is understandable.

However everyone's situation is unique and i think they should be more forthcoming in installing what the customer wants. I guess its a bit like going to the hairdressers (Cue the Flame throwers! )

 

[bengasman]

very true. i fit mostly worcesters and sometimes a vaillant if the customer insists. i still have to get the first customer who is not happy with the end result. well, apart from one, who i reported to corgi and hse for having a polish plumber alter the system after i installed it. polish bloke changed the gaspipe, caused a gas leak, altered the condensate pipe so the fumes could leak into the room and cut the bonding. still, i think they are unhappy with me and rather than the boiler

 

[gas4you]

Does the vaillant have an immersion backup?

Yes, with an option for a second to be installed if needed.

 

[gas4you]

On the features list it states 25 year warranty.

I stand corrected Shows how long it is since I looked at Santon products. It must be a relativley new change. About time though as they all come out of the same factory a mile down the road from me