Advice on Boiler Upgrade

burly

Hi all,

I currently have a Myson Apollo 40B Boiler about 15-16 years old and am trying to decide if its worth replacing it.

In the 5 years I am in the house, the boiler hasn't broken down, but I do service it every year.

When trying to decide to upgrade to a high efficiency gas boiler, I am trying to compare efficiencies and therefore try to estimate the payback.

Accoridng to the manual for the existing Myson Apollo,(which I still have!), the boiler rating says output is 11.7kW for an input of 14.7kW. This ratio of input to output is about 79%. Is this a reliable albeit simple measure of the efficiency of the existing boiler?

SEAI's Harp Database estimates the efficiency at 65%, and I have gotten conflicting views from plumbers who all gave me different estimates for the efficiency of the existing boiler ranging from 65% to 80%.

My conundrum is that if the existing boiler is running at around 65% efficient, then the payback on an upgrade to a 95% condensing boiler would be about 6 years based on my current consumption and a quote of €1500 for the boiler upgrade.

If however, my existing boiler is running ok at around 78-79% efficiency, then the payback goes out to around 11 years, a bit too long for my liking.

Would really like to hear back from plumbers/energy auditors etc who might be able to help me make a more informed decision.

Many thanks.

shane 007

Realistically, your existing boiler's efficiency is in the realms of 70%.
Modern HE Sedbuk would be 90% plus the gain of a fully modulating boiler that will suit the demand accurately! thus reducing boiler over-shooting the demand.

Add some even basic controls such as room thermostat with electronic 7 day programmer & you will make even more savings. Spend more & upgrade to full time & temperature controls & qualify for grant assistance.

You can try for carbon credits for limited controls & receive about €235 from your costs.

DGOBS

Your Myson Appollo, has a permanent pilot light, if you do leave that on all the time (most do) thats €150 per year to run, before you count your efficiency.

Estimating a boiler efficiency at 79% for that boiler is as it was new out of the box, at 15-16 years old, more likely to be at the 65-70 mark, where as your new boiler has your 95% (plus your going to gain more with modulation and assuming the installer will upgrade controls and flush the system there is a lot more potential for savings, anywhere up to 30% or more in total if all said and done correctly IMHO)

burly

Thanks guys for the replies.

Yeah I have thought about getting the controls too. I'm being quoted around €2700-€2800 for a boiler upgrade + controls. Less the grant of €560, I'm looking at around €2250.

My annual current spend on gas heating is approx €850. I could accept a maximum payback period of 6-7 years, but that would mean I'd need to be saving around €350 a year. is that likely with a new boiler + controls?

How much extra do the controls reduce your consumption by roughly?

mark17j

My mother had the Myson Apollo installed when she moved into her house 17 years ago, they are a great little boiler, never had an issue with it, hers ran off the attic not the mains, but recently it began setting off the C-M alarms in the house everytime it was in operation, got a RGI engineer out to look at it and he declared it a hazzard and disabled it... she replaced it with the ideal logic 18kw boiler with 5 years guarantee, this one feeds off the mains, she had made big savings with bills and is very happy all round.
Allot here say it's a basic boiler, but we find it fantastic, the rads do be hopping here, she also got new rads installed with it with temp valves. hot water after a few minutes - that's all you want really.
The boiler upgrade cost her 2200 which included chemical powerflush.

JohnnieK

Look at it this way.

Taking your current usage and heating time's into account if you got the full upgrade package you would be saving 15-20% on you current costs per annum at the price your paying for gas.

What i find with customers is that they start using the heating for longer than they did before and some of them no longer use there electric immersion during the summer and forget to factor in the saving on that when they are making there calculations.

If you just change the boiler with out any control your saving would only be in the region of 5-7%.

burly

JohnnieK wrote: »

Look at it this way.

Taking your current usage and heating time's into account if you got the full upgrade package you would be saving 15-20% on you current costs per annum at the price your paying for gas.

What i find with customers is that they start using the heating for longer than they did before and some of them no longer use there electric immersion during the summer and forget to factor in the saving on that when they are making there calculations.

If you just change the boiler with out any control your saving would only be in the region of 5-7%.

5-7%??

That seems very low compared to what others are saying! Not worth it for those savings IMO

JohnnieK

burly wrote: »

5-7%??

That seems very low compared to what others are saying! Not worth it for those savings IMO

I've seen some places quoting 45% which is ludicrous.

The thing about your boiler is that parts are rare and the one's you can get are expensive compared to when the boiler was lets say 5 years old.

DGOBS

efficiency difference on the boiler is 9-10% IMO, most of the gain would/should be got from the flushing and cleansing of the rads/pipework, a boiler that modulates (3% or so the be gained there) and piper controls (used and times and set correctly) could add up to 30% (I did a similar setup on my own (oil) system and lowered usage by over 40% (and taken about 10% off due to a mild winter)

burly

DGOBS wrote: »

efficiency difference on the boiler is 9-10% IMO, most of the gain would/should be got from the flushing and cleansing of the rads/pipework, a boiler that modulates (3% or so the be gained there) and piper controls (used and times and set correctly) could add up to 30% (I did a similar setup on my own (oil) system and lowered usage by over 40% (and taken about 10% off due to a mild winter)

One plumber that the best way to work out savings is just to reduce your annual spend by the same percentage as the difference between the old boiler and new one.

I.e If a new boiler is 95%, and old one is 75%, then my heating consumption in KWh will be down by 20% as a result.

From what your saying above, that is a load of nonsense then?

JohnnieK

burly wrote: »

One plumber that the best way to work out savings is just to reduce your annual spend by the same percentage as the difference between the old boiler and new one.

I.e If a new boiler is 95%, and old one is 75%, then my heating consumption in KWh will be down by 20% as a result.

From what your saying above, that is a load of nonsense then?

There is no 95% efficient gas boiler out there to the best of my knowledge. There all between 90.1 to 92%.

SEDBUK or HARP would have the stated efficiency of all boilers.

You said the pay back would be 11 year's or so, your Apollo won't last another 11 year's.

DGOBS

lol..lucky it's lasted this long!!

But don't rule out the cost of running that pilot either

I think where efficiencies catches everyone is net & gross, the SE boiler will be quoted in gross, the HE in net, and can appear a bit smoke and dagger 'not for my next trick'

But still, there would be around 10% net gain between those 2 at least, maybe a few more with modulation.

If it's just spending money to reduce heating bills.....insulate, insulate, insult, and if theres a few bob left over.....insulate some more, reduce your heating demands, then controls, finally boiler upgrade

burly

DGOBS wrote: »

lol..lucky it's lasted this long!!

But don't rule out the cost of running that pilot either

I think where efficiencies catches everyone is net & gross, the SE boiler will be quoted in gross, the HE in net, and can appear a bit smoke and dagger 'not for my next trick'

But still, there would be around 10% net gain between those 2 at least, maybe a few more with modulation.

If it's just spending money to reduce heating bills.....insulate, insulate, insult, and if theres a few bob left over.....insulate some more, reduce your heating demands, then controls, finally boiler upgrade

Ive about 400mm in the attic, and getting the walls pumped tomorrow. The windows and doors are not great heat loss wise, but too expensive to replace.

Maybe Il see how I go through another winter with the new wall insulation and see how I go. Maybe wise to hold off on the boiler upgrade for another year.