So what happened in Blackburn?

[ban-all-sheds]

Also a proportion of people will turn off their tvs, toasters, washing machines when not in use but boilers will be left connected to the mains at all times....

A lot of people leave their DVD/HDD/ PVRs running to record programmes while they are away...

 

[crystal ball]

We suspect non PVC wiring by the age of the property, anything built since the 1970s is assumed to have PVC

Next time you look at a piece of PVC T&E look at the voltage it is rated for, in the worst case voltage will not exceed this, similarly for accessories (not a guess lots of national testing and confirmation with manufacturers, also about 40 years experience of this sort of fault nationally).

Older wiring is not to these specs.
Yes we will do a full PIR to confirm the state of the wiring. At one time we used to do all properties but never found any faults on PVC systems. (though we found very few on older wiring)

fair enough

 

[bernardgreen]

It does reinforce my view that combi boilers are the work of the devil since they fail, and when the fail you are stuffed with no backup for hot water or heating.

For "Devil" read

[1] lazy plumber who does not want to install tanks and pipe work in lofts
[2] greedy plumber who wants to make money from a combi install when a replacement heat only boiler will be the only thing necessary

one of type [2] tried to persuade an old lady to have her house re-plumbed for a combi when all she needed was a replacement boiler.

Rant over. there are honest and sensible plumbers. I happen to know both of them.

 

[JohnW2]

[For "Devil" read
[1] lazy plumber who does not want to install tanks and pipe work in lofts
[2] greedy plumber who wants to make money from a combi install when a replacement heat only boiler will be the only thing necessary

I think you are over-generalising - I've seen a good few situations in which installing a combi boiler has seemingly good sense. It's not just the loft tank, but also the HW cylinder. For example, one of my daughters lives in a tiny c1800 cottage and by removing the CW tank and HW cylinder (and installing a combi) she was effectively able to gain two rooms - one unusably small 'bedroom' becoming a usable size after incorporation of the 'airing cupboard' and one in the (again tiny) roofspace, which would not really have been practical with a tank in it.

There's also teh consideration of curring costs. For those who are in their houses for only relatively brief periods, storing hot water doesn't necessarily make sense.

So, I think there are two sides to this story!

Kind Regards, John.

 

[SimonH2]

I think you are over-generalising - I've seen a good few situations in which installing a combi boiler has seemingly good sense.

I don't disagree that they have their applications, just that I reckon these are significantly less than the number installed.

There is reason 3 for people fitting them. Developers so greedy to squeeze another shoebox (which an estate agent will later call a flat) into the space that they won't allow the few square feet of space required for a cylinder. IMO, where a new build has a combi, it is almost certainly a case of 3 - a greedy developer who doesn't give a s**t about whether the property is actually usable, only about how cheaply they can throw it together.
I've seen so many examples where a tiny extra outlay during build would have made a huge difference - but to do it later would be impractical or expensive to do later. In the block where I own a flat, they could so very easily have had a large cellar under the other two flats (mine has a garage under) and it would have cost very little to build in. It's impractical now as apart from digging out a large volume of infill, it would need to foundations lowering which is not easy or cheap under an existing building. So instead, the two flat have f**k all storage space instead of a large storage/utility space.
And several of the houses could easily have had garages.

OK, rant over !

Still doesn't alter the fact that with a combi, you are completely stuffed if the leckky goes off, the water goes off, or the gas goes off - hat trick. And you are completely stuffed when it breaks down.

 

[bernardgreen]

I did NOT write

I think you are over-generalising - I've seen a good few situations in which installing a combi boiler has seemingly good sense.

I have seen only one or two places where the difficulty of installing a heat only boiler and associated pipework and tanks makes a combi a valid option.

 

[JohnW2]

I don't disagree that they have their applications, just that I reckon these are significantly less than the number installed.

Goodness, I certainly wouldn't disagree with that, but you could say the same of so many things these days - perhaps starting with the number of '4x4' vehicles to be seen on the streets of our cities !

Developers so greedy to squeeze another shoebox (which an estate agent will later call a flat) into the space that they won't allow the few square feet of space required for a cylinder. IMO, where a new build has a combi, it is almost certainly a case of 3 - a greedy developer who doesn't give a s**t about whether the property is actually usable, only about how cheaply they can throw it together.

Again true. Mind you, if there weren't 'cheap and nasty shoeboxes' around, I imagine that even less people would be able to get their foot on the property ladder, so I'm not sure the developers can be totally blamed - they are building for markets which exist.

Still doesn't alter the fact that with a combi, you are completely stuffed if the leckky goes off, the water goes off, or the gas goes off - hat trick. And you are completely stuffed when it breaks down.

It would be difficult to disagree with any of that, either. Mind you, loss of electricity, water and gas supplies for significangt periods are so rare these days that I'm not sure it's a major issue.

Kind Regards, John.

 

[JohnW2]

I have seen only one or two places where the difficulty of installing a heat only boiler and associated pipework and tanks makes a combi a valid option.

That may be true, but I gave you an example - essentially a 'one up, one down' Georgian cottage with a small late Victorian or Edwardian rear extenstion providing a small kitchen with a tiny bathroom and even tinier 'box room' above it. Removal of the DHW cylinder (hence airing cupboard) and water tank in the roofspace made all the difference.

Kind Regards, John.

 

[bernardgreen]

essentially a 'one up, one down' Georgian cottage

Which I agree is a place where using a combi would be sensible.

 

[mattylad]

If either the leccy or the gas goes off or the system breaks down you are generally stuffed with either type of system.

Having an aga might be OK though

Both combi and the hw cylinder type use a pump dont they?
Thats the leccy going off stuffing them.

If the gas goes off then your instant hot water systems are all off unless they are electric only.

If you get a high voltage electric spike then both types of system can be damaged.

So irrespective of whichever type of heating or hot water system someone has, the effect of this spike has likely damaged both.

If it didnt I am sure there will be those that are claiming for a new one anyway.

 

[JohnW2]

If either the leccy or the gas goes off or the system breaks down you are generally stuffed with either type of system.

I think Bernard's point was that, with a 'conventional' plumbing system, you have stored hot water even if gas and electricity both fail (and even if water fails as well), and that one also has stored cold water if the water supply fails. Valid points but, as I've said, supply failures are so rare that they are hardly worth 'planning for'. Death of a combi is more likely, and then one will, I agree, be stuck without hot water.

Kind Regards, John.

 

[bernardgreen]

My lack of preference for combi boilers is due to

[1] complexity of the equipment

[2] cramped assemblyof the boiler / pump / pressure control system making servicing access difficulty ( hence expensive )

[3] turning on a second hot tap affects the flow and/or temperature at the first tap turned on. Shower going cold when covered in soap is not pleasant and the temperature dial is turned up. When the second tap is turned off the shower gets too hot.

[4] need to "maintain" the system as regards checking the pressure in the system and if necessary topping up the pressure. Not easy on some boilers where the tap / filling loop is not easy to access. Some people do not have the technical skills to do this and have to call in a service person or next door neighbour just to keep the system running.

Need I go on ?

 

[SimonH2]

I did NOT write

I think you are over-generalising - I've seen a good few situations in which installing a combi boiler has seemingly good sense.

Sorry, missed clipping out one of the quote sections

If either the leccy or the gas goes off or the system breaks down you are generally stuffed with either type of system.

I think Bernard's point was that, with a 'conventional' plumbing system, you have stored hot water even if gas and electricity both fail (and even if water fails as well), and that one also has stored cold water if the water supply fails. Valid points but, as I've said, supply failures are so rare that they are hardly worth 'planning for'. Death of a combi is more likely, and then one will, I agree, be stuck without hot water.

Indeed.
Not only that, but most systems with a hot water cylinder also have an immersion heater, so when the boiler breaks down you can at least keep the hot water going.

My lack of preference for combi boilers is due to
...
[3] turning on a second hot tap affects the flow and/or temperature at the first tap turned on. Shower going cold when covered in soap is not pleasant and the temperature dial is turned up. When the second tap is turned off the shower gets too hot.
...

Yup, all of those, but especially the limited hot water flow rate. In my flat the boiler is rated to nearly 30kW and still can't manage what I'd consider a decent flow rate without going cool - takes ages to run a bath. But it also can't cope with the sort of flow rates needed to make the central heating work sensibly.
I installed a thermal store at the end of last year, so the boiler works better, the central heating works better, and there's an immersion heater as backup (for the heating as well as hot water).

OK, it doesn't have any stored water, but it still has stored heat - so if the lecky is off then there's still hot water for a while. If the gas is off, then the immersion heater will provide hot water and heating indefinitely.
The boiler hasn't broken down once since I ditched using the combi function on it - it used to pack in quite regularly.

 

[mattylad]

You are missing the point guys, even if they store hot water, with such a surge they will all likely be knackered.

 

[westie101]

Just a point of order, here is a definition of Power Surge

power surge

An oversupply of voltage from the power company that can last up to 50 microseconds. Although surges are very short in duration, they often reach 6,000 volts and 3,000 amps when they arrive at the equipment. Power surges are a common cause of damage to computers and electronic equipment

As I commented earlier the raised voltage conditions can last a lot longer than this, in fact until we get to site and disconnect supplies.
So no this was not, by definition, a surge