Why doesn't everyone hate combis?

coffeehound

Apparently combis are now the UK's most common boilers. That being the case, I have a question: why doesn't everyone hate them?

They seem popular here, too. Well it is a money saving site and combis are presumably cheaper to buy and fit I suppose.

From personal experience in perhaps six or seven properties fitted with combis, they exhibit common issues:

• Long delay (typically a minute or so) before hot water comes out of a tap.
  
• Flow-dependant temperature, sometimes meaning that for properly hot water, only a slow flow can be used.
  
• Bizarre and infuriating tendency to slow down the hot water flow until eventually it is a trickle, at which point the boiler switches itself off and (having wandered off to do something else) you come back to a cold trickle coming out of the tap!
  
• Pause the hot flow even for a moment, like if you accidently knock the shower lever, and the damn boiler immediately shuts down. You then have to wait (again) while the water goes alternately hot and cold until the wretched thing has got its life together.
  
• And of course during the household's morning ablutions, the boiler can only do one thing at once, so the central heating goes off and the house goes cold...

How and why do people put up with all this inconvenience? With everybody supposedly too busy these days to even look up from their phone while they are walking, why do they tolerate standing like a lemon at a sink waiting for water to run hot each time they want to brush their teeth or wash a mug?

Compare with a tank-fed system: You turn on a tap to whatever flow you choose. It will run hot typically within five seconds. The flow stays the same until you turn it off again. The water temperature is predictable and largely constant. The water tank can be heated overnight so that it doesn't interfere with the heating coming on in the morning. Perfect, yes?

Is it like Emperor's New Clothes and people get told a combi is the thing to have by the installer (who just wants something quick and dirty to fit) so the homeowner goes along with it and then feels obliged to recommend them to others?

I genuinely cannot understand their near-universal popularity. They seem like such a backward step. Happy to be convinced otherwise though

flashg67

As opposed to heating a full tank of hot water to just wash your mug? And how long are you running the hot water for it to let the house go cold!

No system is perfect, but having had both,on balance, I do prefer a combi

iammumtoone

Houses are getting smaller especially new builds tanks take up a lot of space.

When I brought my house the hot water tank was in the bedroom! Therefore I had a combi boller fitted.

I do get some of the issues you describe but I wouldn't call them problems.

• Long delay (typically a minute or so) before hot water comes out of a tap. I never want a bowl/bath of completely hot water, this is no different to running all hot and having to put a bit of cold in at the end just the other way round, In fact I would say its more convenient.
• Flow-dependant temperature, sometimes meaning that for properly hot water, only a slow flow can be used. This is probably the worse thing but it only happens occasionally and I can carry on with washing up/bathing whilst waiting for more water to fill in.
• Bizarre and infuriating tendency to slow down the hot water flow until eventually it is a trickle, at which point the boiler switches itself off and (having wandered off to do something else) you come back to a cold trickle coming out of the tap! Never experienced this
• Pause the hot flow even for a moment, like if you accidently knock the shower lever, and the damn boiler immediately shuts down. You then have to wait (again) while the water goes alternately hot and cold until the wretched thing has got its life together. Again never experienced this
• And of course during the household's morning ablutions, the boiler can only do one thing at once, so the central heating goes off and the house goes cold... heating goes on and off via a thermostat anyway, a house that is already heated to correct temperature is not going to go cold for a few minutes interruption with the radiators off

I did have a decent boiler fitted at the time, I refused to get a cheap one I am not sure if that makes a difference, it really needs replacing now as its very old, when I can afford it I will be getting another combi. I prefer the extra space, having said that if I had a bigger house I would go for a tank as an airing cupboard would be bliss to have.

The other thing I remember from living at home was the tank would run out of hot water :eek:

Carrot007

coffeehound wrote: »

Long delay (typically a minute or so) before hot water comes out of a tap.

Depends where the tap is I guess. Bathroom, say 20 seconds, warm in 8, Kitchen probably yes a minute. Who cares. A hot water only heater would be the same and a cylinder sucks for many reasons.

coffeehound wrote: »

Flow-dependant temperature, sometimes meaning that for properly hot water, only a slow flow can be used.

Really? Mine seem to heat more the faster the flow. I have nice hot showers on full blast for as long as I like. Electric would cost a lot more and a cylinder would run out eventually.

coffeehound wrote: »

Bizarre and infuriating tendency to slow down the hot water flow until eventually it is a trickle, at which point the boiler switches itself off and (having wandered off to do something else) you come back to a cold trickle coming out of the tap!

Not seen it, you sure you don;t have dodgy plumbing or a stupidly small boiler? You need a high rated boilder for the hot water. Radiators are not relivant and will run of anything (well as long as you are not have 20 of em!)

coffeehound wrote: »

Pause the hot flow even for a moment, like if you accidently knock the shower lever, and the damn boiler immediately shuts down. You then have to wait (again) while the water goes alternately hot and cold until the wretched thing has got its life together.

Don't have shower levers in supid places. And no, not really. it gets hot nice and quick. Again is your boiler small and nasty?

coffeehound wrote: »

And of course during the household's morning ablutions, the boiler can only do one thing at once, so the central heating goes off and the house goes cold...

How long are you doing stuff for so it goes cold? Are you in the north pole? Try setting the timer to come on early enough to heat up the house nicely before you get up. Even if it went off then it stays warm for hours. Do you have no walls so heat just leaves?

PasturesNew

My sibling has an 8 year old house - with a tank in the cupboard that's HUGE - it's a bit like NASA in there .... with some programmable wall panel I bet she's never touched/understood. I hate opening that cupboard to get a towel out.

Other systems are available, but, it's about cost/space.

Owain_Moneysaver

Advantages:

Never runs out of hot water
Mains pressure showers
No cylinder/tank required - in small flats where space is £10k per sq metre that is a very big factor

SuzieSue

The main issue I have with combis is that if it breaks down, you lose the hot water as well as the heating. Most tanks have an immersion heater so even if the boiler breaks you still have hot water.

I would only get a combi if lack of space meant that there was no alternative.

Heedtheadvice

I prefer a hot water cylinder, for lots of reasons such as the ability to heat from a solar source, but they do have their downsides too such as space and running out of hot water with a lot of use.


Given your list of problems I suspect that you have several 'faults' and a properly designed and installed combi system should still work quite well.


Some reasons that combi systems are preferred are that you need not purchase a storage tank (holding many a litre of water that is heavy and can flood) up high to give a head of water, no need for a hot water cylinder/insulation (expensive and requiring space, and a control system, extra pipe work, replacement every so often), no need for pumps to give a powerful shower, and higher efficiency (in terms of they only heat approximately what is needed rather what one predicts by way of storage so less unused losses).
I am sure there are other reasons.......

kerri_gt

Owain_Moneysaver wrote: »

Advantages:

Never runs out of hot water
Mains pressure showers
No cylinder/tank required - in small flats where space is £10k per sq metre that is a very big factor

This

SuzieSue wrote: »

The main issue I have with combis is that if it breaks down, you lose the hot water as well as the heating. Most tanks have an immersion heater so even if the boiler breaks you still have hot water.

I would only get a combi if lack of space meant that there was no alternative.

Found out that for whatever reason our last house had a tank..and no immersion, just the switch that should have been for it that lit up but wasn't actually connected to an immersion, which was capped off.

Personally I love the fact I only heat hot water as and when needed...and OH can have a bath whilst I still have hot water if I need to wash up.

Doozergirl

I've lived with combi boilers for 30 years and I don't recognise what you're talking about. There's something wrong with the systems you're talking about.

We don't use two showers at the same time as the pressure does drop (temperature remains consistent), but we never ever run out of hot water and it is consistently hot and reliable.

The water has no influence on the heating.

I really have no idea what you're talking about. I've not ever had a complaint about a combi system and clients who move from combi to a traditional set up complain about running out of hot water.

adandem

I could have had a standard boiler for less money than our combi.
Main advantages to me are:
Instant hot water.
Excellent water pressure on hot tap and shower.
No tanks of hot water sitting in the loft.