Going Green isn’t easy

[otherclive]

Our 1988 house has a gas central heating and hot water system using a hot water vented tank combined with a large mains fed header tank in the loft to “pressurise” and distribute the hot water. The Worcester Bosch condensing boiler and associated hot water tank are 11 years old. There are two aspects of the system that we don’t like. One is the two header tanks in the loft, and the other is a monsoon pump system to feed the en-suite shower. The en-suite was installed by the previous owners. So we began by looking at the possibility of replacing the vented hot water tank with an unvented pressurised one which would allow loft tanks to be drained and isolated, and would allow the monsoon pump to the en-suite shower to be got rid of. Then at some stage a new boiler would replace the existing one. It wasn’t to be as the airing cupboard would be too small for anything larger than a 90-110 litre unvented tank. Then a 22 mm mains feed would be required from the kitchen to the new tank. That’s when issue two cropped up, as the mains feed to the house is only 15 mm, so routing a 22mm pipe from kitchen to airing cupboard would still not provide adequate pressure and flow for a three bathroom house. The other option to get rid of the loft tanks would be a Combi boiler which would still be subject to output fluctuations when parallel services were being used, and still require a monsoon pump to the en-suite. At £7k+ not on your life.

So our son suggested why not consider a heat pump system, with the government grant of £7500 the overall cost can be on a par with a new boiler and tank installation.. Once my wife had reconciled herself to absolutely no gas in the house as part of any grant financed installation I had some interesting discussions with EDF, EON and OCTOPUS. Based on the survey that we had carried out for the new boiler/tank options it seems the airing cupboard is too small for the HP hot water and buffer tanks. It would need extending in to my office/ spare bedroom. Plus all said that they could not accept a 15 mm mains supply from the meter, and a new 22mm minimum supply would be required. So no point in getting a new EPC, or testing ceilings and soffits for asbestos, or lifting patio or drive to look for water pipe runs it’s not going to happen.

I now know why our elderly neighbours decided only to go for a boiler replacement around two years ago when they wanted a HP system. Guess we will continue with gas for as long as we live in the house and let our successors decide how to deal with it in years to come.

 

[Hutch]

I fully agree about grants NOT being easy to acquire, you really need to be on some sort of a benefit. So we didn't have a hope.
Two years ago we changed our hot water and central heating system from a vented system to a pressurised system. Got rid of the 200gallon water tank in the loft and the combi boiler went into the airing cupboard with the hot water tank. Got rid of two water pumps for the showers, the mains pressure was equal to the old pumps, and the Aqualisa showers already had thermostatic controls.

We wet for a Valant Combi boiler which has Stainless steel internals where as the Bosch an Ideal had Aluminium internals10 year guarantee.
The boiler was about £1750, replacing a Cast iron New Mexico which was 40 years old and working well. Everything done in 4 days. Total cost about £5500.

 

[Sam Vimes]

Nothings easy as it's made out to be is it?

Two of the other issues that I've read about with heat pump systems is that some don't do a good job of providing hot water. Also if retrofitting in a house with radiators, they may be too small by about 30% because of the reduced water temperature circulation.

Technology does progress over time so maybe some of these issues have or will go away.

 

[otherclive]

Our radiators were fine as they are all double connectives three years old, but Octopus said if their on site survey showed any to be inadequate to achieve the design performance then any upgrades would be included in the quoted price. Must say their website and technical agents were excellent, but we had decided not to go for the paid on site survey.

My dream is to go all electric, as we had such a system fitted with thermostat panel radiators in our first home. No worries about pipe sizes, flow rates etc. Minimal servicing or maintenance with few complexities.

 

[Hutch]

Nothings easy as it's made out to be is it?

Two of the other issues that I've read about with heat pump systems is that some don't do a good job of providing hot water. Also if retrofitting in a house with radiators, they may be too small by about 30% because of the reduced water temperature circulation.

Technology does progress over time so maybe some of these issues have or will go away.

My brother changed to an Air source heat pump, about 5 years ago, he moans about the house not really getting warm, about 20c max, Never asked him about domestic hot water, but his electric bills are about 20% higher than our combined gas /electric bill, for his small 3 bedroom house as opposed to our bigger 4 bedroom . But he has only just changed to Octopus energy for Heat pumps. So this winter might see a change.