combi boiler benefits

DVardysShadow

I have a combi boiler and I hate it. In my last house we had a baxi back boiler and I dealt with the plumbing and the controls and had hot water when I wanted it from a cylinder. We got all our hot water for 300 ft^3/week, all summer, no immersion required. When people came to view the house for sale, they used to say 'Oh it hasn't got a combi? We like combi's, ours is wonderful'

Now we have a combi, I hate the slow slow hot water and the wait to fill a bath. We hate the lack of a warmed airing cupboard. And I hate the money that has to be spent to keep this complex beast running and the fiddling to nurse it along while waiting for a repair man. On our baxi, I spent £60 on one repair in 15 years. On our combi, I have spent £75 for 1 repair and I have another repair being quoted. In 15 months, that is 2 repairs.

They meet a need where space is limited. But when people say 'they are wonderful You get instant hot water', they are not as good as a well designed conventional system. Our combi is running in the summer giving us hot water for 300 ft^3/week, but no airing cupboard.

jennifernil

DomtheMon wrote: »

I love my combi boiler. Yes we had problems in the first few years bu had it over 8 years now and love it. I'd not disagree that they might not be as reliable BUT advantages?

1. Not heating a tank of water that you don't need
2. The space saving (gets rid of water tanks)
3. Not needing to heat water with electricity in the summer and then even more wasteful
4. Hot water on demand. Have a bath or shower whenever you want!

Why would you want to heat water with electricity in the summer when you have a perfectly good gas boiler to heat it?

aboard_epsilon

DVardysShadow wrote: »

I have a combi boiler and I hate it. In my last house we had a baxi back boiler and I dealt with the plumbing and the controls and had hot water when I wanted it from a cylinder. We got all our hot water for 300 ft^3/week, all summer, no immersion required. When people came to view the house for sale, they used to say 'Oh it hasn't got a combi? We like combi's, ours is wonderful'

Now we have a combi, I hate the slow slow hot water and the wait to fill a bath. We hate the lack of a warmed airing cupboard. And I hate the money that has to be spent to keep this complex beast running and the fiddling to nurse it along while waiting for a repair man. On our baxi, I spent £60 on one repair in 15 years. On our combi, I have spent £75 for 1 repair and I have another repair being quoted. In 15 months, that is 2 repairs.

They meet a need where space is limited. But when people say 'they are wonderful You get instant hot water', they are not as good as a well designed conventional system. Our combi is running in the summer giving us hot water for 300 ft^3/week, but no airing cupboard.

It's sort of obvious why they push the things .. (not getting at the plumbers here, but many/ some/ lots, of plumbers in general)

1. Minimum amount of brain power needed to install them compared with system boilers or conventional condensing boilers.

2. Much easier ..less hard work / manual labour, to do on the install.
3. They make work for them ..cause they will break down more frequently. $$$$
4. Some..probably all, will need replacing at least twice in a 30 year period...ensuring they have work for many years to come. $$$$

yes there are lots of benefits ..but only for mr plumber.



all the best.markj

C_Mababejive

So we agree then?

The combi efficiency myth is largely a misrepresentation touted by people who either dont understand engineering and scientific principles or who have a hidden agenda

Combis are largely mis sold to many people who would fare better with a system boiler.

dander

Well, I can't say I recognise the claims about unreliability. I had a combi boiler in my last place for 12 years without ever needing a repair. Moved into current place with back boiler, which limped along miserably for a few years, struggling to heat the house and I hated every moment of it! Not had my lovely new boiler for a year yet, so I can't offer an opinion on how reliable it is.

I guess a lot of it is down to what you are used to though. I've lived in houses with combis since the 80s so I simply can't get my head around anything other than hot water on demand. Maybe other people have bigger tanks of hot water than my house did - or liked shallower baths but I even with one person in the house I certainly couldn't manage on one tank full of hot water a day -with the old boiler, I had to give the tank time to reheat (slowly) between doing the washing up and having a bath.

Wading into the discussion about efficiency - and I should stress I don't know anything about this, I'm just asking a question! Doesn't a system boiler keep the tank of hot water at a fixed temperature, so everytime you draw down some hot water, it will refill with cold so the boiler will fire up to reheat anyway? And with a thermostat controlled heating system, the boiler is constantly coming on and off anyway to maintain the heat of the house?

Domthemon

My comments about heating with electricity are because the old boiler here worked by pumping the central heating water in a coil around the immersion tank. So when the central heating was on that constantly heated the tank but when it was off eg in the summer you either put the immersion on or would have to close all the rads but still have hot pipes running all round the house. Neither very efficient.

Yes a combi is coming on and off every time you turn the hot tap on/off and I will concede you are heating water left in the pipe that you haven't used, but with an old system with a tank you either heat water you don't need or can run out when demand is higher. To me the convenience of having any amount of hot water whenever I need it is a massive plus. I hated having to plan ahead to have a shower, and finding I had wasted a tankful of hot water at other times.

Each to their own. But to hint that those who like combis are somehow deluded is a bit much, but then there are a lot of people on here who think anyone who believes different to them are deluded!

googler

brig001 wrote: »

There is a myth of efficiency around combi boilers. Our boiler runs once in the morning and gives us enough hot water for the day. Compare that with a combi which fires up every time you run a hot tap. Which is most efficient now? There are pros and cons on both sides and it's not as clear cut as you might think.

Are you sure you're not heating more than you actually use, and having the excess cool off in a tank, then have to be reheated next time the boiler fires?

Whereas the combi just heats what is needed, when it's needed?

aboard_epsilon

see BLUE

dander wrote: »

Well, I can't say I recognise the claims about unreliability. I had a combi boiler in my last place for 12 years without ever needing a repair...was it a condensing combi Moved into current place with back boiler, which limped along miserably for a few years, struggling to heat the house and I hated every moment of it! Not had my lovely new boiler for a year yet, so I can't offer an opinion on how reliable it is.

I guess a lot of it is down to what you are used to though. I've lived in houses with combis since the 80s.....we are on about here ..coindensing combis so I simply can't get my head around anything other than hot water on demand. Maybe other people have bigger tanks of hot water than my house did - or liked shallower baths but I even with one person in the house I certainly couldn't manage on one tank full of hot water a day -with the old boiler, I had to give the tank time to reheat (slowly) between doing the washing up and having a bath.

Wading into the discussion about efficiency - and I should stress I don't know anything about this, I'm just asking a question! Doesn't a system boiler keep the tank of hot water at a fixed temperature, so everytime you draw down some hot water, it will refill with cold so the boiler will fire up to reheat anyway? And with a thermostat controlled heating system, the boiler is constantly coming on and off anyway to maintain the heat of the house?

only in the winter months


all the best.markj

aboard_epsilon

googler wrote: »

Are you sure you're not heating more than you actually use, and having the excess cool off in a tank, then have to be reheated next time the boiler fires?

Whereas the combi just heats what is needed, when it's needed?

if the tank is well insulated ..it could take a week for it to loose the heat in it ..its even better than a thermos flask.

all the best.markj

dander

So if it's the condensing side of the combi that makes them less reliable, why doesn't the same reliability issue effect all condensing boilers? (again, not sniping, just genuinely curious.)

And surely no matter how well insulated a tank is, if it's refilling with cold water every time it's used, you are still reheating for every top up - admittedly not from cold, but you're having to apply that heat throughout the whole body of water. If you switch your boiler to only heat up the tank once a day, then you spend the whole day adding cold water to your tank of hot water and diluting the heat.