Doing a bit of a refub on the house and changing from oil heating to gas heating. Know nothing about gas heating but with 2 teenage daughters in the house seem to regularly run out of hot water so the gas heating being instant appeals to me. Any advice on what to specify? Should I go for a combi system or retain the hot water tank?

Cheers for any advice.

Combi is easiest, with electric shower.
Bigger house with lots of bathrooms probably a mains pressure HW tank off a system boiler. (I think that’s what they are called).

Whats the insulation like ?
We’ve had solid wall insulation on ours & the heating hasnt been on half as much. (Not been that cold though this winter, to be fair, but house is more comfy). (And no damp!!!).

House is 1940’s but has cavity insulation at some point. Have an oil fed aga which drinks oil and a 30 year old oil boiler so hoping to get some efficiencies when we change. Only 2 showers so not too bad on that score one powershower though so system needs to be able to keep up with it.

Mains gas or LPG?

Hows your budget? Megaflo will give you loads of mains pressure hot water,no need for pumped anything so long as incoming main is suitable.Combi will only provide a certain amount of hot water at a certain usage rate, check DHW flow rate,again no shower pump needed dependent on main.Standard boiler with larger more efficient cylinder would be fine,check out recovery rates for the cylinder.HTH.

You will not be able to retain the power shower if you switch to a combi.

Need to know info about the amount of water outlets in your house as this would have an influence on combi or mega flow.

When we refurb’ed our boiler we went from a water tank storage to a combi, which was right for us in our circumstances.

Sounds like I need to get someone to look at it and advise me properly, its the kind of thing I only want to do once and rolling it into a few other improvements so happy to put the cash into getting the best solution – within reason!
Never heard of Megaflow – have to start googleling!

Have an oil fed aga which drinks oil and a 30 year old oil boiler

Why not just add a boiler to the AGA, taking hot water off it doesn’t really impact oil usage.

We’ve an oil-fed AGA and with just ‘domestic water’ as opposed to ‘central heating’ we get plenty of hot water.

http://www.agaliving.com/our-products/technical-help/domestic-hot-water-from-your-aga-heat-storage-cooker.aspx

Look at this one:

eBay item number: 141163701204

Just replaced our old oil boiler with mains gas ( mains gas is relatively new in N Ireland and is being slowly rolled out across the country)

Went for the Boch combi boiler ( cant remember exact model but its the latest and biggest available from Phoenix) and its perfect. We have one shower which is an old mixer type – its now got mains pressure and is excellent. Retained original radiators which now heat up much faster. We no longer have a hot press as the tank was unnecessary and removed.

Our house is 4 bedroomed detached bungalow and around 30 years old and cavity wall insulated. The new system is faster, much much quiter and so far significantly more economical. We also qualified for a grant towards replacing the old boiler so the whole thing cost 1800 ( oddly enough all the quotes from the “approved contractors” were pretty much the same 😉 )

No regrets at all – installation was fast and painfree. 2 days for mains installation and 2 days for boiler. There is about a 6 week lead in from Phoenix ( main NI Supplier)

First question to answer is it mains gas you are going to?

I have been told that modern combis can pretty much heat HW at mains pressure, so it’s very rare to need a HW tank anymore. The only advantage of a tank is you can have an immersion heater so when the boiler dies you can still get HW.

Combi’s are good but you need to understand that if it is rated at 15l/min at a 35degree rise in water temp then it can only deliver that to 1 outlet, ie if you open 2 taps then you will get 7.5 l/min to each, 3 taps 5 l/min and so on.This is fine and very workable as long as you understand the limitations. Best to get a good heating engineer or two round to see whats required.

If you have enough mains flow rate and pressure go of the MegaFlo, if not the Combi route but a local plumber can check that for you easily.

Have a look at the SEDBUK website for boiler efficiancies and costs:

http://www.boilers.org.uk

CF

Thanks Chaps

On mains gas already, just use it for a gas fire so should be easy to hook up.

Aga already heats the hot water but we converted it to a thing called a snugburner which claims to use less oil but not totally convinced. For reasons that I cannot fathom its not as good at heating water but this could just be due to us now using more water due to growing family. If I keep it as a wet Aga then I need the hot water storage tank so can’t go Combi. I am struggling to find any data on whether removing the wet box from the Aga would make it use less oil. If I can heat the water as a by product from the Aga without burning more oil than gas for the same effect then it may make sense to do so.

Penguini that sounds very encouraging, will drop you an email and maybe have a chat to you about it.

Cheers for the advice, the problem with the internet is there is so much information out there its hard to filter out the relevant!

Penguinni you got a megadeal, WB 42cdi around £1200+vat plus flue,controls etc.
A-B, if you have the budget/mains pressure you will not regret going Megaflo.A good engineer will be worth his weight in sorting you a top system,have a look at RM cylinders,same 25yr guarantee for joe public money.Whatever way you go do fit the best you can afford.

Aga already heats the hot water but we converted it to a thing called a snugburner which claims to use less oil but not totally convinced.

Not heard of that, nut just Googled it – £2k!

Our AGA uses 8.0l per day, just left running. Hot water wise it’ll be 2 baths a day quite happily but we’ve also an electric shower – so never without.

br – I think it saves on oil but should have put a flow meter in before shelling out £2.5k to install it. BTW if you ever need any aga bits I have all the wick oil burner bits in the shed!

We’ve just updated our system – pressurised tank is a gazillion times better than a combi.

And i went from a crap tanked system to a good combi like night and day – its sized to the water usage not the heating requirement,

Get a couple heating engineers in to see what options you have and the benifits and draw backs of each,

One thngs for sure – crap tanked system or crap combi and itll be crap.

Btw – we chose the tank as we moved to a bigger house with en-suite and have two young girls – that means lots of water usage as they get older and want to shower lots.

I know what you mean, brother in law used to have a poor combi system and the shower was a trickle. Will speak to some companies this week, am leaning towards keeping the hw storage tank and the aga heating the water but will have to see what folk say. Worried about a pressurized system leaking like a sieve in my ancient plumbing!

Why keep the Aga? As a cooker they are renowned for the staggering amount of oil they use. Mate got rid of his as he thinks it was using more oil as a cooker than the central heating was using to heat a 5 bedroom house. Sell it to someone and buy a gas cooker. Probably be able to buy a gas cooker and have money left to part fund your heating. Oil Aga are just conspicuous consumption as it does not do the job better than a gas cooker/range.

SD- I hear ya! I have my bikes the wife has her Aga, seems fair to me!

(although a few k of extra oil is a lot of bikes….)

. aaron-bangor – Member
SD- I hear ya! I have my bikes the wife has her Aga, seems fair to me!

(although a few k of extra oil is a lot of bikes….)
Point it out occasionally ie when you fancy a new bike!

Thread update, budget dictated that I went down the combi route and pretty happy with it. Ripped the water box out of the Aga and glad I did as it was slightly leaking when exposed!

House heating is superb, cant believe how much better it is than the oil system it replaced. I was sceptical of the boiler size the builder put in but seems well up to the job. Seems to be better to work them hard for the condensing bit to be efficient allegedly?

Had to turn the electric motor off on the power shower though 🙁 not just as good as it was but its OK. A megaflow would have been better but a lot more money.

Building work is crap though! been out of the house for 4 weeks, no kitchen for 8 weeks! back to normal by this weekend I hope, might even get out on my bike if I am not painting!!!!

When I had a combi a change of shower head to one with less holes gave it more vigour.