UKC

Last time my central heating was fixed I was not present,but there was some sort of mild/moderate leak within the boiler, and the plumber said that I should consider replacing it in the near future. Now I am at the near future.
I don't know whether to get a conventional boiler, but if I do then do I get an on-demand type, or the balanced flue type that keeps the cylinder of heated water in my airing cupboard. Otherwise, do I consider a wood-chip boiler(advantages vs disadvantages) and do they fit into the same category as wood burners, which are to be banned from central London in the next two years due to pollution?
Alternatively do I consider the air-exchange device, that is always described as a reverse fridge in action, or what about extracting the heat from pipes installed in the garden? How sensible is it to consider photovoltaic cells? What are the economies of this? I heard in the last week that they can damage the stability of your roof. Another consideration is the viability of the national grid to supply energy consistently.

So quite a lot to consider.

In reply to veteye:
Do you have a gas supply? If so I'd go for a gas combi. On demand hot water is great (bin your electric shower if you have one, it's basically a mains pressure gas shower and it's wonderful), and the new technologies are expensive and a bit niche for now.

In about 10-15 years (the typical life of a boiler) those technologies will have matured, I think then will be the time to switch.

Go for a quality brand, Worcester Bosch is what I have and is often recommended as the best, and wasn't even that expensive. Don't get British Gas to fit it, they're a rip-off, price up local options instead.

In reply to Neil Williams:

Yes we have gas. My son has a Worcester Bosch of about 6 months old, so he cannot say too much as it has not been used much. I just wondered about other options as they are increasing in popularity(I think) and so there must either be good marketing or a good reason to consider such devices.

In reply to veteye:

Conventional for me. We have a large bath and very rarely use the shower. Filling the bath in winter may take ages, and could mean a drop in temperature in the radiators whilst doing so. Also nice to still have an airing cupboard with a tank in it. If the Gas/Boiler goes out, you still have the Electric immersion to heat your water.

JMHO of course.

In reply to veteye:

.........Just to add. We are still using the same boiler that the house was built with, 1987. Apart from a little Kettleing, it's still holding on.

Touch wood!!

In reply to veteye:

I think without too much research, I'd consider a gas boiler, but with a storage tank in the airing cupboard which is well insulated and compatible with other systems. A lot of renewables based systems require a hot water tank to function properly, as they don't generate the high-power heating that you can get out of a gas boiler. This could then potentially mean that you can upgrade in future - either by upgrading the complete system to something different, or by adding parts to it (PV, solar thermal, heat pump etc.), and reducing your dependence on gas with time.

Do you have a south facing roof? Solar thermal is a good option for heating in terms of pure energy efficiency, but PV can be more flexible. My parents, for example, have PV on their roof (I think about 3kW), but switched in such a way that they first use the electricity to power their appliances, but if they are producing more than they are using, then it gets fed into the hot water tank via the normal electrical immersion heater. Only when that's hot does it get fed-in to the grid. If they're using more than they're producing, then they pull the extra electricity from the grid. There's a gas boiler as well to cover any long periods where there's no sunshine. They end up with a small electricity bill and a virtually non existent gas bill as most of their energy comes from the PV, but they don't have to worry about being cold. They do have the advantage that they are retired, so it's slightly easier for them to use the washing machine/dishwasher during the day when it's sunny, but nonetheless the system is modular enough that you could start with the gas boiler and tank, and add the PV later if-and-when you have the money.

In reply to veteye:

Looking at my spreadsheet, I paid less for heating oil at my last fill up than I did in 2010. I wonder how gas and electricity heating prices have fared over the same period?

There aren't many utility advantages to living in a village but oil heating has certainly been the bees knees for quite a while. None of that messing around with standard charges and unit tariffs to compare, no ringing up and hanging on for 30 minutes waiting for Eon/BG/NPower etc to answer.

At my last house I changed from gas to oil as it was cheaper. Whether its set to continue though is anyone's guess.

PS I would def consider air source/ground source if starting again. The man two doors down has it and it seems brilliant.

In reply to veteye:

I'd go for a gas combi boiler with a built-in storage tank which at set times is heated and stored, this gets over the only irritation I have with combi boilers where there is a delay between turning the tap on and the boiler firing up and heating the water.

In reply to veteye:


There is strong marketing. I think they're on the cusp of being good options (like say electric cars) but not quite yet, so one more conventional boiler would to me make sense.

In reply to gethin_allen:


Mine has this feature and I turned it off because the flow on my shower is high enough that it goes hot, cold, hot. It's also a bit of a waste of energy keeping it hot.

In reply to veteye:

We've just had ours changed, we had an old conventional boiler that had been in since the house was built over 20 years ago and it was getting a bit tired.

After looking a various options we went for an unvented system, it gives us mains pressure hot water but with a storage tank for the hot water.
Wanted to avoid a combi as they still have problems with flow rate when the inlet water is at it's coldest in winter and can suffer when mutliple demands are put on them for water in a larger house.

So far the new system is brillant but it's early days yet, also I'm told the unvented systems are compatible with solar panels if we want to add them at a later date.

In reply to veteye:

We have a conventional gas boiler which heats water in a pressurised tank. This obviates the need for a header tank in the loft and is so well insulated that you can put your hand on it and not know if it's hot or cold so the heat loss with keeping it hot 24/7 seems to me negligible. It also gives you equal pressure in hot and cold taps which is good for shower mixers and for filling a bath. Another thing which may be of interest is we now have a solar PV array which includes a gizmo to divert any power you're producing but not using into your immersion heater. By judicious timing, we make use of any spare power this way rather than export it to the grid.

In reply to veteye:

I have Air Source Heat Pump + Solar PV + Solar Thermal. I had nothing to start from (no mains gas, no radiators, no existing central heating). Total cost £22k. It's very quiet, amazingly warm, and heats my large house for £800 / year electricity including all other electrical use for a family of 4. Oil would be about £1500 / year. I get about £10k back for the heating (RHI over 7 years) and £500 / yr for solar (25 years).

Given oil installation was going to be £9k, I break even in 4 - 5 years. There are also a few fringe benefits in terms of child safety (can't burn on rads or hot tap) and house temperature (stable and warm, much better than any gas CH house I've lived in).

As Solar PV feed in has dropped, I would probably drop that part if I did it today until batteries become more cost effective.

In reply to veteye:


Second opinion? Boiler parts can be pretty cheap.


There's nothing to stop you using the features of a combi-boiler with a thermal store if it's plumbed so hot water is drawn from the tank while available then via a thermostatic mixer direct from the combi. A thermal store boosts the efficiency of a combi boiler if it's carefully installed and use is made of the heat it leaks (not much use in summer!). They really only make financial sense where you have mixed sources, solar thermal, woodburner with back boiler and a gas/electric heater.

Proposals for London are as I understand it to ban all but the cleanest (DEFRA approved) woodburners, effectively rolling out the patchy street by street 1950's 'smokeless zones' to cover the whole city, I haven't heard a blanket ban discussed and were there to be one I suspect it'd be a blanket ban on new installs with a long transition to a full ban.


Long term heat pumps are the best solution we have for domestic heat (where additional heating is required). Right now the price may not make sense for you. Worth a look for sure.


Separate issue really. Any badly done work can damage what it's done on. I guess subsidies are currently at or around the point where an average user not being clever with their electricity consumption will just about break even over the half life of the panel but you'd have to do some calculations for your install and consumption to verify that. Suppliers are limited/regulated so prices basically just track subsidies, there's not much of a true functioning marketplace.

Solar thermal is very likely worth having especially if you're faced with replacing your existing system. There are a number of implementations, you'd need to speak with a knowledgeable installer to work out which works for your needs and budget.


Unless our political and economic situation deteriorates markedly there's no reason to suspect the grid will collapse.
jk

In reply to Babika:



I haven't researched it but I was under the impression that oil worked out more expensive than gas these days?

Thankfully, the days of being forced to deal with Eon/BG/NPower are over. There are now loads of smaller providers. They aren't all good but many of them are far cheaper and offer far better customer service than the big six.

In reply to SDM:
Yeh - as a user of oil in my current and last home I wouldn't use it if I was on mains gas....

Tankered Oil and Tankered gas (as opposed to gas through a nice pipe) are both a lot more expensive to use as a simple result of having to get a bloke in a large lorry to drive to you and deliver it at vast expense. And oil or LPG heating boilers are I suspect more expensive to buy and service than comparable normal gas as they don't have same economies of scale... they are rarer and folk to service them are rarer and more specialist too.