New Boiler help

alag20

Hi Guys,
It is time for me to replace my boiler as the current potterton [which is over 12 years old] is coming to an end of its life.

I have a semi detached house with 3 double bedroom, 1 double bedroom sized shower, 2 WC, 2 reception, a kitchen dinner, utility room and a landing. The house has a relatively new [2006] hot water tank which is in excellent condition. Can someone confirm that 28KW would be sufficient for the property as it is about 14 odd radiators?

I am looking for a new boiler and have narrowed it down to two.

1. Potterton Gold 28HE - £660 inc VAT incl standard flu.
2. Vaillant EcoTech Plus 428 - £ 850 inc VAT, excluding flu.

Can someone please advise the pros of Vaillant over Potterton or vice versa? They are both 2 year warranty.

Also on top of this what else should i be expected to get done. I have been told for a MagnaClean [ebay sells them for £70 - does anyone know any cheaper], a new 22mm pipeline (strangely from gas meter to half way it is 22mm and then it is 18mm), powerflush and thermostats on radiators (as only some radiators have individual thermostat). Can someone please advice if there is anything else I should be looking out for or if something here doesnt add up?

Further more, I live in Greater London area and the price quoted for labour for the above is £600 [well no vat as will be paying cash] by Gary Plumbing. Can someone advise if this is reasonable as the guy seems professional and seems to know his work?


Thanks in advance for your help!
Manish

CAN1976

Don't know about the Potterton, but I had a Vaillant installed about 14 months ago. It is saving me money on my gas usage, and is performing A OK as regards heating water / the house. I also had the magna clean. I went with a locally recommended company and paid about £1700 all in. I was lucky enough to get a £400 rebate from the government as my old boiler was permanent pilot light.

alag20

CAN1976 wrote: »

Don't know about the Potterton, but I had a Vaillant installed about 14 months ago. It is saving me money on my gas usage, and is performing A OK as regards heating water / the house. I also had the magna clean. I went with a locally recommended company and paid about £1700 all in. I was lucky enough to get a £400 rebate from the government as my old boiler was permanent pilot light.

Thanks. I was originally going blind eye with Vaillant but just thought i would ask as the difference is massive £250.00

BIG_2

The Potterton Gold is a combi boiler which doesnt make sense if you are retaining the hot water cylinder.

Also 28Kw is a big boiler if its heat only. You should look at the energy trust website and get instructions on how to do a full house boiler size calculation.

ziggyman99

BIG wrote: »

The Potterton Gold is a combi boiler which doesnt make sense if you are retaining the hot water cylinder.

Also 28Kw is a big boiler if its heat only. You should look at the energy trust website and get instructions on how to do a full house boiler size calculation.

It could be the 28kW system boiler.

I do agree with you. 28kW would heat a huge house. If you have loft insulation and double glazing I reckon 18kW tops. Do a whole house boiler sizing though. Don't be tempted to oversize. It makes the boiler inefficient and can cause premature failure.

Personally, I believe Valliant produce the finest boilers on the market at the moment. I wouldn't touch the Potterton. It's a revamped 15 year old design and really isn't that good.

BIG_2

Sorry not really up on Potterton products - wouldnt touch them either. I would go for Worcester Bosch or Veismmann and take advantage of their 5 and 6 year warranties

gas4you

I agree, 28Kw sounds way too big for your needs.

The Potterton Gold is an ok combi boiler. It is exactly the same boiler as the Baxi Duotec and platinum and the Main boiler.

The only difference is the warranty offered on each.

The Gold is soon to be replaced with a new boiler.

Avoid the 428 at all costs. The Vaillant 400 series are nothing but trouble.

alag20

gas4you wrote: »

I agree, 28Kw sounds way too big for your needs.

The Potterton Gold is an ok combi boiler. It is exactly the same boiler as the Baxi Duotec and platinum and the Main boiler.

The only difference is the warranty offered on each.

The Gold is soon to be replaced with a new boiler.

Avoid the 428 at all costs. The Vaillant 400 series are nothing but trouble.

What do you mean? Which series to look at then?

Also 400 series is open vent according to their website which means it requires a cold water tank in the loft which i do have. The only other series which Vaillant do in the UK is 600 which is system boiler which works of direct mains.

Further more, i agree that 28KW is more than what my property should take. Ideally it should take a 24 / 26 KW but the closest vaillant / Wosterbosch or others that do are either 18KW which is too small or 28 KW which is too big. Please advice what to do?

BIG_2

If you need 24kW why not look at the Worcester Bosch Greenstar RI 24 kW or if you prefer the system boiler the Greenstar 24i

alag20

BIG wrote: »

If you need 24kW why not look at the Worcester Bosch Greenstar RI 24 kW or if you prefer the system boiler the Greenstar 24i

Please forgive my naive ignorance in advance. Doesn't a 28KW boiler mean it will need to run less than a 24KW as it is a system/regular boiler. Can someone please advice how is it inefficient as my understanding is that boiler is a big kettle. It heats and circulates and cuts off when water is at a particular temp!

Pincher

alag20 wrote: »

Can someone please advice how is it inefficient as my understanding is that boiler is a big kettle. It heats and circulates and cuts off when water is at a particular temp!

You are absolutely right, for a traditionalist view.

If you accept turbo boost gives more bang per buck on a petrol engine because there is some residual energy in the exhaust gas, then it should be easy to accept that the plume that comes out of the flue (chimney) has some residual heat. Condensing mode boilers pass the returning water from the radiators (or hot water cylinder) through the exhaust to pick up the residual heat. If the returning water is still hot, it won't pick up the heat, and you say bye bye to all that lovely energy as it goes out the flue.

So you have a whole load of sensors telling the boiler computer what's hot and what's cold, and it turns the flame up and down to try and make use of the residual heat if possible.

If your boiler is not able to turn the flame (modulate) down when the house is warm, then the returning radiator water will be hot still,
and not able to pick up the residual heat, hence inefficient.

A tradiational non-turbo boiler is probably 70% efficient, whereas a turbo (condensing) boiler is 90% (Band A) efficient.