Another Boiler question

[Chris]

Originally Posted by landlord

Would stay away from Heat Pumps unless you have underfloor heating and a thermal efficient house up to current building regs. Otherwise you would be wasting your money.

I have an air source heat pump and its fantastic. Our house if double glazed but the glazing is 20 years old so its not great. Also the insulation is not up to current standards.

We don't have underfloor heating (although we would love to) so do have to run the system at a higher temperature to run rads however it works.... the house is warm and we get 300 litres of hot water (50 degrees) a day and our fuel bill has more than halved from the previous calor gas system.

If you are replacing your rads anyway then an airsource would be a good idea to consider as with modern rads they still work. They are very simple systems and ours has been fitted for 2 years without any issue. There is nothing to service on it so basically its fit and forget.

HOWEVER. since fitting it the coldest temperature we have seen here in Gloucestershire has been about -10 and it worked OK althout it was running flat out to keep up but if you were regularly at -10 or more then it might not be for you.

[BogMonster]

Originally Posted by willk

I notice that Bog Monster (despite his name) has avoided mentioning that sensitive subject - peat. The islanders burn an average of four metric tons per annum each for domestic heating.

Probably in a non-condensing environment

About 20 years too late for that old chap

Our old camp house has a peat Rayburn in but it gets about a week's use a year if that, and nothing on earth would persuade me to go back to peat in a house I lived in! Probably 90% of houses used peat post-war, probably less than 5% as a main fuel now, just a few sittingroom fires and a handful of masochists, sorry, traditionalists.

No, it's got to be oil, and while I'm slightly intrigued that an air source heat pump might be interesting in the future, I want something I can get and install in the next month, which means local purchase.

I've been canvassing experience locally and some of the boiler repairers have a low opinion of the life expectancy of condensing boilers and say they'd fit the old type if it was their choice.

All info is good info, ta

[willk]

Originally Posted by BogMonster

About 20 years too late for that old chap

Er, sorry. I must have been misinformed.

Oil be more careful in future...

[landlord]

Chris how old is your house ?

I think your lucky to have a heat pump that works so well in a retrofit installation with an encumbent heating system, especially at -10. The COP value at -10 would be quite low and the heat pump would probably be inefficient, most are rated down to -5. Furthermore 50 degrees hot water is below the normal setting of 55 to 60 degrees.

However it sounds like your house has a very good thermal efficiency rating and few drafts, which reduces the air changes and therefore helps to maintain the ambient temperature. This is where heat pumps excell, by maintaining ambient temperature of 19 to 21 degrees, boosted by a secondary heat source such as wood burners.

It sounds like you've got your system set up just about right for your property which is good to hear. I have heard of numerous complaints about ASHP's in older properties.

[Chris]

The house was built in '69 it does has some cavity insulation and is fairly draught free.

When we installed it we did replace some rads with larger ones to get the best out of the lower temperatures it runs and the long term plan is to put underfloor in to really get the best from it. However even running it this way it's still so much cheaper than Calor or oil PLUSS this year we start getting the RHI payment of around 2k per annum for the next 7 years.

[m chappelow]

Not that it will effect the new modern boilers but Some of the 1960s & 70s built semi detached houses in the village where I live had a lot if the old type boilers fail after they owners had decided to put bedroom extensions over garages and had roof lofts fitted out into bedrooms kitchens extended & conservatory s built all having new radiators fitted without thinking what the boiler could handle in some cases the boiler was working its b,,,ks off flat out where the boiler was initially designed to run say 6/ 7radiators the thing was running 12 or more .

[camelgas]

A boiler that works hard and is not short cycling is miles more efficent, also the back-end temp (FGT) will be higher so less chance of it rotting out quicker.

I am interested to get some more info on your system chris, any chance of the following information.

1. size of unit in KW and the make

2. system load in KW

3. House type and plan, ie: semi detatched bungalow

4. approx cost of electric used per year

5. room stat setting in 'c

6. timer run time in hours per day

I have no direct expierence of this type of system but others in the trade have slated it when we chat in the merchants, so it would be interesting to know the above information , as your system clearly works and you are happy with it.

[willk]

Oh look, I've found a gauntlet...

[camelgas]

no gauntlet , just interested in the technical aspects .

[willk]

Originally Posted by camelgas

no gauntlet , just interested in the technical aspects .

Well, it's been a while since Chris has had a Technical Challenge. Let the Games commence

[Pikey Dave]

Originally Posted by willk

Well, it's been a while since Chris has had a Technical Challenge. Let the Games commence

Oi! behave yourself

[IanH]

Whilst I have the opportunity to get a cheeky couple of questions in...

Can a gas boiler serve both traditional radiators and underfloor heating or do the two type of heating have disparate temperature requirements?

Also, what are the chances of successfully physically moving a boiler? We have a perfectly good boiler, recently fully rebuilt courtesy of British Gas at one end of our house and looking to build an extension that would have a utility area which would be mid house. This utility area would be approx where our existing hot water tank is now which would be replaced by new HW tank sited in the new utility area. Wondering on the practicalities of looping the circuit at old boiler end and tapping into the circuit mid circuit.

Ultimately this utility area would be used to site some form of renewable energy source but i dont think we are quite there financially and technology wise but having an interim solution utilising the existing infrastructure combined with underfloor for the new rooms (bathroom, toiler, kitchen) would be good to achieve. The idea of moving the boiler to new location is it would allow us to achieve a dry loft.

[Pikey Dave]

Originally Posted by IanH

Can a gas boiler serve both traditional radiators and underfloor heating or do the two type of heating have disparate temperature requirements?

Assuming it's a conventional gas boiler (i.e. not a combi) then yes it can serve both. The underfloor heating is a closed loop that is controlled by a thermal mixing valve, so it regulates its own temp. Our conventional oil boiler feeds traditional rads in the old part of the house & underfloor in the west wing

[IanH]

Thanks. It is a standard boiler but in the future I may purchase either a heat pump type unit or a gas system boiler ie seperate hot water tank like a conventional boiler but radiator pipes pressurised and sealed system to avoid the need for an external tank in loft. However if requirement of underfloor would prevents the use of a system boiler then it would not be the end of the world.

Trying to keep options open as with lighting I think that we are at a crossroads regarding traditional type thinking being pushed to the limit of what it was designed for and newer technologies that were designed specifically for energy efficiency in our climate. Currently there is still no mainstream replacement for gas/electric/oil boilers and in this country, alternatives seem to be an expensive curiosity that works well for some but not for others.

[camelgas]

moving a non condensing boiler to a new extension is not likley to be allowed, check with your local building control. Part L of the building regs , the conservation of heat and power is what you want to get them to check under.

[Pikey Dave]

Originally Posted by camelgas

moving a non condensing boiler to a new extension is not likley to be allowed, check with your local building control. Part L of the building regs

Best not to tell 'em then

[camelgas]

building control will not sign the job off unless it complies with the standards in force , so you have to play their game.

[Pikey Dave]

Been there done that. Get the ext'n signed off, then start on the real work when the busy bodies have buggered off back to their desks.

[camelgas]

[BogMonster]

Originally Posted by Pikey Dave

Been there done that. Get the ext'n signed off, then start on the real work when the busy bodies have buggered off back to their desks.

Nice one