Combo boiler or not?

sexymandy

plea please help!
I can’t find any information on the internet on whether I would be best to switch to a combi boiler. Many years a go I was advised not to bother because it would take many years to save the money I’ve actually spent on it so it would make more sense to wait till my current one breaks.
now with the energy rises I’m wondering whether it would now be worth it?
im currently in a 4 bedroom house that’s occupied by 2 adults 2 kids.we have one bathroom. Our current boiler is an ideal icos. It’s pretty old but we were told it’s quite a good one? I’m not sure how efficient it is ?🤷‍♀️

Reed_Richards

A combi boiler could save you money if the pipes between the boiler and your hot taps are short and well insulated.  As a retrofit into a larger house that is less likely to be true.  I used to have a combi boiler but it had been lazily installed so the hot water from the combi went first to the airing cupboard where the hot water cylinder had been and then back out to the hot taps.  This meant I had to wait an age to get hot water out of a hot tap and a large quantity of hot water ended up trapped in the feed pipes which wasted a lot of energy when it cooled.  

lohr500

There are a few Icos models listed in this database :  

https://www.homeheatingguide.co.uk/efficiency-tables?make=Ideal

They all look to be around 90% efficient which is pretty good. 

I have never been a fan of combi boilers because every time we have stayed at friends' houses who have them, it seems to take forever to fill a bath. Perhaps due to bad installation in each case? If you have two kids, then I imagine you will have quite a high demand for hot water.

If it was me, given the efficiency of the existing boiler, I would keep it until it suffered an expensive breakdown and only then consider replacing it.

Have you already looked at other ways to make the existing system more efficient? 

• Running the central heating with the room thermostat set a degree or two lower?
• Setting the boiler thermostat lower so the return water temperature is below 54 deg C ( allows the boiler to run in condensing mode).
• Making sure there is plenty of lagging on the hot water cylinder.
• Fitting thermostatic valves to the radiators so you aren't over heating rooms that don't need as much warmth.
• Checking that there is a good depth of insulation in any loft spaces.
• Fitting draught excluder strips to any windows or doors that have gaps.  

All these things will help reduce your running costs.

Magnitio

Hot water cylinders lose heat all the time. This can be 50-100W, or more if they are old and not well insulated. They can also be inefficient to heat from a boiler, depending on the distance between them and the state of the coil in the cylinder.

A well installed combi-boiler will use less gas (and electricity), but you may have some compromises e.g. running the hot tap in the kitchen whilst someone is in the shower, or as others mention, the time it takes to deliver hot water to the tap.

If you have don't run baths all the time, and particularly if you have an electric shower, then a combi boiler usually makes sense.The payback period for making the change will be lengthy, so if your current setup is reasonable, you may be better waiting to see what happens during the next couple of years with electricity and gas prices and consider the option of a heat pump.

Apart from that, the recommendations above regarding making your existing system and house as efficient as possible are well worth pursuing.

Brewer21

If it heats the hot water sufficiently and likewise the radiators then keep with it. 'If it ain't broke......' saying.
I had another combi fitted around 6 years ago, the last one lasted 24 years before I finally said goodbye to it.
It just wasn't doing its job in the end, getting the heating system (radiators) up to a decent heat output nor heating the hot water very well. What we did know after the new install and a few months had passed, the systems were obviously more efficient (hurray! hot water and radiators too) but the actual gas electric usage were about the same, more bang for you buck as they say.
You'll never really recoup the outlay for a new boiler in saving on your bills, it'll be a darn site more efficient though for your outlay.

And good advice above re making what you have more efficient, like lagging the loft/pipes/cylinder etc if it's not already been done.