Are condensing boilers all bad ?

[John Rumm]

A bit of it yes...

[Tony Bryer]

My Honda Jazz was far more complex than my 1962 Mini and far more reliable. A well-designed modern boiler should be more reliable than one with thermocouple, pilot light and mechanical thermostat and the good ones are.

[geoff]

In message , tony sayer writes

I'll get Godot onto it

[YAPH]

It's not just the condensing function: being *able* to condense means the boiler can recover more heat from combustion without having to worry about hitting the dew point and having acidic condensate rotting the works. Which, given that standard efficiency oil boilers even more than gas ones tend to be very crude steel boxes with water jackets and a big flame up the middle, may well allow a large increase in efficiency without condensing a drop of steam.

[Rob]

Well, I meant the master stat doesn't control the rads - they do it themselves with their own stat. The master stat isn't much more than a switch. In my ideal system ;-)

Rob

[tony sayer]

Is that at 20 or 5 % Dave?.

Why should VAT be levied on such a necessity anyway?..

[Dave Liquorice]

"Domestic Energy" so 5% like domestic gas and lecky.

Very good question. When did 5% VAT come in on domestic energy, ISTR it happening but can't remember if it was a rise from zero rated or a fall from 17.5%, I suspect the former.

[dennis]

It was added as a carbon tax to reduce consumption. It was added as VAT because the mechanism to collect it was already in place and was the cheapest option. It backfired because it was called VAT and not carbon tax. Many are in favour of carbon taxes but scream when VAT is mentioned.

[Terry Fields]

Thermostats only have a 'max' setting, and switches only have an 'on' position.

DAMHIK...

Terry Fields

[Huge]

Because they can.

You're correct.

[Mark]

In that case it would save more money to move to a smaller house.

[Martin]

We are on our second condensing combi boiler.The one lasted 17 years.

[dennis]

Hmm, if they all lasted that long it might just be worth swopping my 29 year old boiler. I estimate it would save me about £60-£70 a year. Were there any additional servicing costs in those 17 years?

[Martin]

The maker offers a 16 years guarantee ATM. The normal guarantee was 3 years, with the actual boiler being guaranteed for 16 years. The maker recommends a service every two years.

We had an annual service contract. The amount changed but it ended up costing about £150/annum including replacement parts. The boiler was very sensitive to cobwebs restricting incoming air flow.

[dennis]

That screws the economics.

I had to vacuum an ants nest out of mine once. All the flying ants were dead where they tried to fly through the burners. It didn't affect the boiler and I only found out as part of my 5-10 year clean it out routine.

I think I will just carry on with the old one until the greens offer to pay for a new one.

[S Viemeister]

Wasn't it briefly at 8%?

[Andrew Gabriel]

Wouldn't work with my thermostats. They go up to 35C, but if you set them to 30C or higher, my software will assume they're faulty and not use the setting, falling back to using a default setting. (The thermostats are Satchwell ones which just turn a potentiometer and I read the resistance/setting by computer.)

At various times, the thermostats are ignored anyway, and the setting comes from elsewhere in the system's configuration.

This reminds me a bit of an interview I heard with New York's traffic controller some years back. He was pointing out that they disconnected all the pedestrian push buttons at traffic lights about 30 years ago, as they didn't want pedestrians messing up the programmed traffic flows. The interviewer commented that there were push buttons on the new lights just installed outside his apartment. The traffic controller said of course - they're there so the pedestrians push the button and wait for the Cross signal, otherwise pedestrians try to run across the traffic. Still doesn't mean we've connected those buttons to anything - we haven't. ;-)

By the way, my original design was to cut the demand for heating in a zone whilst a window or external door is open. The windows and doors are all wired up and sending open/close signals to the heating control, but I never got around to actually implementing that part of the software, as I don't think it's been an issue in my case.

[Andrew Gabriel]

One government decided home fuel should be subject to VAT, which was 15% at the time. It was to be raised in two stages to reduce the impact, something like 7% and then 15% a year later. After the first rise, the goverment lost power, and the next government reduced it to 5%. EU law doesn't permit any country to remove VAT from any item, so it couldn't have gone back down to 0%. In theory the EU should have had to approve the reduction too, but as it was part of that party's manifesto and EU was generally viewed rather badly at the time, they didn't push for this and just accepted it.

[John Williamson]

Round here, they're connected to the little light that comes on and says "wait".

[dennis]

I would have thought the time to satisfy the demand on a wet system would be too slow to react to opening and closing doors and windows, and you still want the same temperature even if the window is open. maybe an alarm to tell them to shut the window would be better?