Central Heating Help

RoadeRunner

I know someone can help me with this !
We bought a large bungalow recently which has 2 vaillant boilers (not Kombi) and a hot water tank which has an immersion heater. The two boilers each operate half the radiators but are not linked to the water heating. We want to change to a better system. The other problem is the water heater tank is in the garage and the bathrooms / sinks are at the furthest point away from them. There is a sytem where you press a button and it makes the hot water instant but if you don't engage this it takes about 10 minutes to get through ! Not very eco friendly or efficient. The first company who quoted for us saif they thought we should keep the systems separate but have 2 Kombi boilers they recommended 2 Worcester 28 boilers and to do away with the hot tank. The second said we should do away with the whole system and have a large heating boiler (magiflow I think he said) and because the pipes won't be big enough we will have to replace pipework and some of the radiators and this will be better than 2 Kombi's. We haven't has a price in for the 2nd one but it sounds expensive. The price is important but not as important as having the right system. All suggestions would be gratefully received as we are very confused !

Canucklehead

Good afternoon: Need a bit more info.. how large is the bungalow (numbers of rads) , how many bathrooms and what is condition of the existing rads/ pipework? If you are interested in a Worcester go to their website and use the 'Find A Boiler' facility http://www.worcesterbosch.co.uk/index.php?fuseaction=boiler.selector&con_id=10227&from_id=10227. For general info on gas central heating (website maintained by a CORGI engineeer in Reading) check out www.miketheboilerman.com or for details on the specification and installation of gas central heating systems visit the Energy Saving Trust http://www.energysavingtrust.org.uk/uploads/documents/housingbuildings/ce30.pdf


HTH

Canucklehead

RoadeRunner

Hi Canucklehead - really sorry its taken so long to reply with family problems and getting quotes for all sorts of things the heating has taken second place until last week when we switched it on !

There are about 20 radiators. There is one bathroom and 3 cloakrooms. We will be having an ensuite in one of the bedrooms. I think the pipework was fitted in mid 80's previously it was warm air heating (very large disconnected boiler in garage) Since we switched it on all the radiators seems to be working although the boilers sound like jets taking off most of the time ! Have had second quote now which came in at £19600 + Vat - I needed a large drink after that one. Any suggestions would be gratefully received

Canucklehead

Hi

If you are still there I will post suggestions.

Corgi Guy.

RoadeRunner

Yes - Still here !!!

Canucklehead

Ok,

How big ,in square metres, would your bungalow be? Roughly.You might need to split the heating zones.
What will you be getting for that amount I'm struggling to see where you could spend 19k.

My suggestion would be, Use one heat only boiler. this can be in the garage.
Fit a large Megaflo unvented cylinder (I think their website will give detail on size to number of bathrooms) www.heatraesadia.com If you can fit this megaflo somewhere central in the bungalow you can have an equal draw off time to all the points of use, instead of the long delay you have now or using the secondary pump to circulate the hot water.(I think secondary circuits are a waste of energy, it's like having a small heating circuit)
All this depends on having a good incoming water mains pressure and flow.
You might need to consult your local water co.
As for the noise from your current boiler/s, it might be a good idea to have someone service them . This will tide you over until you address the whole system. Vaillants (and most boilers) run fairly quietly so the noise you describe could be a failing fan.
You might need to replace/up size some heating pipework so that the system circulates easily and rapidly.Gas pipe probably ok as it's feeding two boilers already, and I would guess the meter is in the garage.

Interesting one this;)

Corgi Guy.

RoadeRunner

Hi again

The bungalow is around 215 suare metres. The reason the quote was so high - apparently - is because they said the gas pipes would need to be bigger from the mains (I hope that makes sense) to accommodate one single boiler and they seemed to think a number of the radiators were too small for the rooms so they would replace most of them runnng the pipework under the floors. They would also have to join the water into the heating boiler as it is separate and remove the existing systems. A second quote we had was for 2 Kombi boilers to replace the existing boilers - connecting the water into each so still running separate systems at £5000 + VAT.

The bungalow as said originally had warm air heating and although the boiler has been disconnected what do you think about re-instating that system with an up to date boiler ? It doesn't address the water heating problem but its another thought.

The water pressure is very good.

Thank you for taking an interest and your suggestions

Lynne

Canucklehead

Hi

I'll stick with the wet heating for now!
Can you tell me what the output of the current boilers are?
Are you saying that the hot water is heated by immersion heaters(electric)?as you say they are not part of the boiler system.

I think you should try to find an installer who might go back to basics and do the following.
Measure the property and work up a figure for the boiler output using the whole house method.
With this figure you can now determine what size boiler you need and, from the tech spec of ,say, Vaillant find the cubic metres per hour gas consumption that boiler requires.

I don't think you need a new gas supply, but then I am only sitting here not where you are!
I feel the two quotes are conflicting, the one for two combis would probably require a new gas pipe as they are gas intensive. A heat only in the expensive quote IMO would not need a new gas pipe.
The problem is that an installer would be reluctant to put the time and effort into working up the heat requirement with no guarantee that he/she will get the job and may well feel that they are just a pricing service.
Are you happy with the heating as it is now? Are the rooms warm ?in other words do you really need the rads that are suggested?

see the links previously posted

Corgi Guy.

Canucklehead

More................

See here... http://www.energysavingtrust.org.uk/housingbuildings/calculators/boilersizing/


Warm air is not my field but here is a link .. http://www.johnsonandstarley.co.uk/default_a.asp

I don't know how much of the original ductwork is left and in what condition it is , but it might be worth a look.
You might find it difficult to get a Corgi who is into warm air.
Personally I think it suits the new highly insulated and draught free buildings that are now required.If you have a return duct to send the stale and moist air to a heat recovery unit then it's very efficient and healthy.
A small heat only boiler could be fitted to provide hot water.I still think unvented (Megaflo) is the way to go with this.

Just out of curiosity where are you in the country?


Corgi Guy.

RoadeRunner

Hi - I had a look at the Johnson & Starley site. They are based in Northampton which is where I live. Armed with your suggestions I am getting a couple more quotes from engineers who know a bit about warm air heating. I agree about some Companies not wanting to quote if they didn't get the job. As far as the existing heating is concerned I am happy with the heat from the radiators and when we get the roof insulated better (its a flat roof - so thats another story !) we should notice a difference. There so much to do in this house its knowing where to begin but I still feel that the heating/water system is one of the most important and I won't be beaten there has got to be a solution !

Lynne

Lynne

gasser9

I also live in Northampton and can tell you that Lennox USA are bringing out a condensing gas fired warm air unit (95% efficient). They have a UK office on Brackmills (Sorry do not have number) but if you are thinking of going down the warm air route then you may want to consider this unit.