what is wrong with combi boilers ?

[swelec]

I have lived in my current bungalow for 18 years

Shortly after moving in, had the old gravity fed coal fired boiler removed for a gas boiler to be fitted

I guess my heating system was a typical system except it was a single pipe one

There was a galvanised cold water tank in the attic which I had to change due to a leak - prior to that, the ball valve was changed to stop a contant drip from the overflow

Then a hot water tank in the kitchen cupboard which again was changed when it sprung a leak

In the cupboard was also the timer and the pump - the pump was changed twice in 18 years

There was one room thermostat to control ?? the heating for the whole bungalow

Then the new boiler

With my limited knowledge, a basic affair, just a gas valve, a burner, a thermocouple attached to a simple temperature controller, and a big block of metal to do the heat exchange

Apart from an occasional clean out ( service ) all I had changed was the gas valve as it stopped shutting properly and there was always some gas escaping causing a larger than normal pilot light !!

So in seventeen years quite a few problems with a simple system

It has now been ripped out and a new combi boiler is in place

The advantages

Extra storage space in the attic as no cold water tank, in the kitchen as no hot water tank, in the utility room as this boiler is much smaller than the original. On demand hot water for bathing / showering. A well balanced heating system with individual TRV's on each radiator

In my opinion, all the separate elements dotted around the house have been brought together into a little box stored an the wall in my utility room - the shiny new combi boiler

What are the disadvantages?

As you can see, I have had a few breakdowns of individual elements of my old system

If this frequency of breakdowns continues with my new system, what is the difference ?

Just because they are all concentrated in one box, is it fair then to give combi boilers such a slating ?

They are a much more complicated bit of kit and so the chances of breakdown of any of the individual parts means it must be more prone to problems than an old style boiler

I just want to understand why there is such an anti combi feeling on this forum

 

[PEDANTICVINDICTIVEMAN]

Not from me there isn't, I said exactly the same as you when the Which magazine said they weren't as reliable as an ordinary boiler, nothing wrong with a decent qaulity combi, problem is with the cheap ones, now condensers, thats another story.

 

[doitall]

Ask again in 6months when it breaks down and you have no hot water for a week.

Or your having a shower while the misses open the kitchen tap or the 30mins to run a bath or,I just don't like them,

 

[PEDANTICVINDICTIVEMAN]

As I said, cheap combi's are crap, I fitted an open flue Worcester 240 about 13 years ago as a replacement for an ordianry one, it's only had a thermocouple in all that time, not bad for a tin can eh, 24 and 28Cdi's I have fitted which I service each year seem to be the same, odd diverter valve but nothing major, maybe a lot is down to the installer with too many hit and run merchants.
We have an Ideal Isar which after a few pcb teething problems works ok, fills a bath no problem, I dont particularly like them and I fitted it as an experiment to see if it is worth fitting for my customers after april, I am still seeing how it goes, takes too long to service but cant fault it's flow rate and it heats the 8 rads and 1 kickspace heater quick enough, works well gas wise with the thermostatic valves and Honeywell CM67 double glazing and cavity wall insulation.

 

[swelec]

Or your having a shower while the misses open the kitchen tap or the 30mins to run a bath or,I just don't like them,

I have fitted an electric shower in our ensuite, I haven't seen a decent shower off a combi yet

My bath takes 7 minutes to fill - just long enough to eat my weetabix in the morning waiting for the bath to get ready

When the family - 3 of us - are getting ready for a night out, all of us can have seperate baths one after another. We dont have to wait hours for a tank of hot water to warm up between baths

 

[swelec]

Ask again in 6months when it breaks down and you have no hot water for a week.

When the old system broke down, I had no heating or hot water either - no immersion heater fitted

Wher is the difference ?

 

[swelec]

Not from me there isn't, I said exactly the same as you when the Which magazine said they weren't as reliable as an ordinary boiler, nothing wrong with a decent qaulity combi, problem is with the cheap ones, now condensers, thats another story.

I am trying to find a simple explanation to back up my argument here which PVM seems to agree with

Unless the new combi is built to a very high standard, surely due to its complex nature compared to an old style boiler it must be more unreliable

BUT is it more unreliable than the whole heating system which it is replacing ?

 

[kevplumb]

if your going to fit a combi how can the rads become unreliable unless they start bursting

FWIW my combi has been in three houses with min probs in 5 yrs

 

[doitall]

My boiler is chugging away at home while i'm stuck in London just as it's done for the last 25 years. cost to date 2 thermocouples, same ;pump, same gas valve, same heat exchanger etc etc etc

Would I replace it not a cat in hells chance till they improve the reliability, now you can take that how you like but i work in the trade and have done for 46 years, and the new boilers are a ripoff by the manufacturers, no other product would get away with what you idiots can't see, Your being screwed big time, so wake up and tell them.

Example, new grundfos pump £45, new combi pump £140, same pump same make, same model, remove the head and swap, saved £100

 

[swelec]

no other product would get away with what you idiots can't see, Your being screwed big time, so wake up and tell them.

Example, new grundfos pump £45, new combi pump £140, same pump same make, same model, remove the head and swap, saved £100

do it all

Thanks for the reply

So that is one valid reason for being anti combi.

Any more ?

PS my education record of 9 O levels ONC and HNC in electrical eng and being a logistics manager for a manufacturing company with a turnover of £50 million hardly qualifies me as an Idiot

 

[swelec]

if your going to fit a combi how can the rads become unreliable unless they start bursting

sorry kevplumb, perhaps I wasn't clear enough

Is a combi more unreliable than the SYSTEM it is replacing ie separate cold tank hot tank room thermostat pump timer boiler and 3 way valves

One item to break down against seven separate items

 

[oilman]

PS my education record of 9 O levels ONC and HNC in electrical eng and being a logistics manager for a manufacturing company with a turnover of £50 million hardly qualifies me as an Idiot

maybe so, but

I am trying to find a simple explanation to back up my argument.......

.......doesn't indicate a desire to hear anything other than what you want to hear. I was beginning to wonder, before you said otherwise, whether you worked in some well publicised branch of the police force, known for their undying attempts to find the truth.......NOT!

Anyway, please fit a combi, they're much better than conventional boilers (at providing work for boiler repairers )

 

[PEDANTICVINDICTIVEMAN]

All modern boilers are crap compared to the older ones, but all that has happened is that plumbing/heating materials have fallen in line with everything else, lets face it everything is crap, merchant and manufactering priceing policies have nothing to do with whether a combi is more reliable or not with all it's components in one unit, or a traditional system with the components spread around the property, yes priceing is a rip off but then so is everything else in this country, look at the price of cars and spares for starters, look at the price of diesel, look at how much you paid your mortgage provider for your house by the time you finished, I could go on and on if you like.

 

[ChrisR]

PS my education record of 9 O levels ONC and HNC in electrical eng and being a logistics manager for a manufacturing company with a turnover of £50 million hardly qualifies me as an Idiot

Only 9? Certainly it doesn't, you need far more that that - like wot I got. I fit LOTS of combis, then wonder why I get moaned at when they fail so much.
They have all the heat in a little boxso they don't last as long; all the bits close to each other so they take longer to get at; water near electronics; you usually can't disconnect or isolate what you want, to help in diagnosis or to keep-the-heat-on until you can do the repair; all parts have to be (supposedly) manufacturures originals so they can rip you off; they're sensitive as hell to any sort of dirt in the system and they don't work if the bloke downstairs is brushing his teeth with the tap on.

And , as one bint pointed out after I'd spent a lot of effort fitting her Euro Mini Hispec EconoMarvel into her poxy kitchen cupboard, they have
TOO MANY PIPES!

 

[PEDANTICVINDICTIVEMAN]

ChrisR I dont know why you seem to have so many problems with what your fitting, I have stuck with the Worcester 24/28Cdi range and had none of the problems you seem to have had, I have fitted them on old one pipe and two systems BF, OF, RSi, using X400 as a cleanser and X100 for inhibitor all to Benchmark with no powerflushing and brand new CH systems using Hep20 all with no problems, I have been doing this for a number of years since the 9.24 range so I cant claim just to be "lucky", I dont work for Worcester and have no vested interest, I dont know what I will be using from April as I am undecided on stainless/aluminium, again I say I dont seem to have the problems you seem to have, I always try to stick the boiler in the airing cupboard so as to avoid pipes in the kitchen using a vertical flue if necesary.