Boiler - what did I do?

[AnthonyL]

Never had a house with a boiler before - just coal fires.

So Baxi 105 is in a utility room which also has a shower. SWIMBO goes to have a shower at the same time as I try her new toy, a household steam cleaner, on some dirty stuff. Next minute a scream - no hot water and the hot water sensor is flashing.

I've made a call out but in the meantime I turned the steamer off, ensured the vent fan in the room was on, and turned the central heating on. Some 10-15 mins later flashing light is off, water is back on and I'm trying to understand what happened. Explanations welcomed.

[Syd Rumpo]

It doesn't matter what happened. It is your fault.

Cheers

[AnthonyL]

That's my wife's viewpoint also.

But then - if she hadn't tried to have a shower the situation would never have occurred.

[Tim+]

Hard to think of any obvious connection unless you have a wiring fault in your house that caused a significant voltage drop in the supply to the boiler when you turned the steamer on.

Tim

[Martin Bonner]

I think we need some more information about the system to understand in what WAY it is your fault.

Does the hot water come out of the taps at the same sort of pressure as the cold water tap in the kitchen?

Is there a hot-water tank?

Is there a cold-water tank?

Is this a combi-boiler? (You may not know).

Does the steam-cleaner have any connection to the plumbing system? (All the one's I have used have just required water pouring into a tank)

[The Natural Philosopher]

BAXI 105 is a combi, ergo cannot even supply one shower with hot water reliably..

[NY]

Why not? Our oil-fired Grant combi boiler can reliably supply several taps (eg bath, washbasin, kitchen sink) with hot water reliably at the same time, so there's no reason to suppose that it will not be able to supply the lower flow rate of one shower.

Like all combis, it can take a while to run hot - and it's a very variable "while" as well, which seems to have no relation to how long since the hot water was last run and therefore a) whether there is water standing in the pipes that has gone cold, and b) whether the pre-heated reserve in the boiler may have gone cold. But once it's hot it stays hot no matter how fast the taps are run.

Having said that, it is maybe significant that when we bought the house, one of the previous owners had installed an electric shower rather than using the hot water feed from the boiler - no idea why.

[charles]

perhaps so that they could have a hot shower in the summer when the Baxi wasn't on.

[sm_jamieson]

A downside of a combi is when supplying hot water there is no heating, so perhaps it was to keep heating on when having a shower. Also, while a combi can supply a good shower, 2 showers is a push, so often a second bathroom will have an electric shower. Simon.

[Tim+]

Why would you turn a combi off in the summer?

Tim

[Davey]

Immaterial. It's something technical, it's faulty, it's your fault. No question. Even if it had never occurred, it might have done, so it would still have been your fault, whatever it was. It's called: The Natural Order of Things, according to Women.

[AnthonyL]

Baxi 105E so I assume combi-boiler? Comes out at mains pressure. Just a little steam cleaner (like a small vacuum cleaner but put water in the tank and plug in the electric mains). Makes a lot of steam though - which I think is the idea.

[AnthonyL]

As I am a complete novice with boilders a little bit more elaboration and maybe an alternative suggestion would be helpful. We've only been here 5 weeks and if there is something I should know it then anytime before winter sets in might be a good idea.

[AnthonyL]

Someone has fitted an electric shower, it is connected to a water tank just above the ceiling - it therefore just shows a low pressure warning light.

[AnthonyL]

So what, if wishing to stay with one boiler, should one have?

[johnjessop46]

Oil fired combi boilers are completely different kettle of fish. They start with a charged heat reservoir which slowly depletes during the draw off. T he burner contributes to the heat taken out but high flow draw off will eve ntually result in the store being depleted and the output temperature dropp ing unless the flow rate is reduced. Usually the shower is over before the output temperature drops. Filling an oversize bath is when the problem beco mes noticeable.

[Tim+]

The mind boggles. You have a combi, and then someone plumbs an electric shower to a storage tank?

Normally storage tanks are removed once a combi is fitted. I think your plumbing system needs a major review, professionally if necessary. Sooner rather than later as a) the Christmas season is upon us and b) the whole set-up screams "clueless bodge". Hopefully there isn't a dangerous bodge lurking but I wouldn't bet against it.

Tim

[AnthonyL]

Oh there is a major bodge. The storage tanks used to be in a wooden frame in the loft - the frame being part of the supporting structure for the roof. A previous owner - more than 11yrs ago, thought it a good idea to remove the frame and board the whole loft. The resulting unsupported 5m purlin has therefore struggled under the weight and I have a sagging roof. That was all raised in the survey and steps are in hand to get it fixed. But yes the plumbing, and I think some of the electrics, require some overhaul. Oh and the tank in the roof is showing signs of corrosion.

The last owner had no idea and no money.

We still like the place.

[Martin Bonner]

Some people don't like combi boilers. I've never had a problem with them. (But I've only used a gas one.) They do need a decent pressure from the mains supply *and* a decent maximum flow rate. They can also struggle to supply hot water to a bath and a shower simulteanously.

Did you get a boiler report when you bought? If not, I'd be tempted to gather advice on a *good* plumber, and get him to have a look at it. (You need personal recommendataion - if you are Cambridge, I'd recommend Gareth Ives.)

[The Natural Philosopher]

There is only one proper way to do CH and hot water and that is with a mains pressure hot water tank, plus if in a hard water area, a proper water softener - ion exchange type.

Plus a system type boiler, or combi adapted to do the same.