BXProject

[Father Ted]

Err yes they are all worked by stats???

No what I meant is, the standard set up has the heating running using a combination of time clocks, the heat controller on the boiler and thermostats either on the valves or room stats - mine does away with the time clocks and is "always on" and relies on the thermostats to control whether the thing actually fires up or not. so long as all the thermostats are happy and not calling for heat the boiler wont come on.

Current gas feed is 15mm- and shares this with the gas hob

[Vanny]

So its not gravity fed then

then let unlit gas back on when it stopped.

You really need to replace your cooker if it does this, cos erm thats not right, not one little bit!

Glow worm do the very best boilers, by a long way.

[Fish_Botherer]

Pardon me for butting in and making a probably feeble attempt to talk sense for a change, but don't most modern gas cookers cut the gas off if there's no combustion? I'm pretty sure it's a feature of any new gas cooker now on sale unless marked as "unsuitable for use in flats". A gas fitter doing a yearly gas check on my flat claimed it was to do with the risk of an unattended pan boiling over and extinguishing the flame (he was saying my old cooker was fine but any replacement would have to be the newer sort). He wasn't trying to sell me a new one...

Or is there some risk of an explosive suckback in the circumstances Phil talked about earlier? Hold on, I'm not making sense there - I'd expect any gas burner to let gas pass on a one-way-only basis, unless it's all to do with an assumption about the gas supply pressure.

Talking to myself again... hopefully not in riddles. The "bx on moon" referred back to a Way2Go razz on BXclub from yonks ago.

[Father Ted]

So its not gravity fed then

Meh! Ive always been told it was a gravity feed system because of how the hot water worked (as Phil says by expansion / gravity - hot water rises cold water falls) and the cold water feed for the whole system is gravity fed via the primatic tank that fees both hot water and heating. Admittedly the heating radiator feed is pumped....

[Philhod]

Yes but that's talking about your incoming water supply, not your operating system.

If the hot water didn't expand up the pipe in the first place there would be no colder water to fall would there. It's the same principle as the pre 55 cars that worked like that, without a water pump. They called that a syphon system???

Tht's just the same as putting mine on permanently FT. Everything runs to whats being demanded from the stats.
I ran mine for one month on full time and another full month with the system shut down from 12pm till 4am, last winter. Admittedly it wasn't that cold but the shutdown month came in only £7 cheaper.

Most appliances over 5 years old and some new ones do NOT have flame out devices, hence the need to increase the dia of your incoming supply pipe when fitting these boilers.
All appliances that do not use an electric supply of some sort will be without flame out devices.

Check with your plumber mate Vanny, he'll only tell you the same.

[Way2go]

This primatic tank seems a bit of a red herring in the discussion FT. You can have hot water gravity fed on an indirect cylinder with pumped central heating or even the simple old style direct cylinder if it's for hot water alone. Newer boilers are fully pumped because they're designed for low-water content and steel heat exchangers would burn out quickly if a certain flow level wasn't maintained to the cut-out point.

[Way2go]

Even newer boilers dispense with the tanks for an on-demand system for HW and a pressurised central heating system.

[Philhod]

Ah! but we're now on about mul;tipoint water heaters which have flash boilers made from thin stainless sheet.

[Father Ted]

Even newer boilers dispense with the tanks for an on-demand system for HW and a pressurised central heating system.

Arr, that sounds like one of those Combi-Boilers that break as soon as winter draws in and then you cant get parts for. Give me a Baxi or GloWorm anyday as I know Im likely to get parts for them for a few years to come. - Gone into a bit of detail over on the MoJo thread about what I think I need to be looking for at mums - actually what she has still works, its just over heating water now and the stuff going to that tank and rads is too hot, OK the thermostatic valves shut off, but thats still leaving the radiators screaming hot for a few mins.

I think Imentioned the neighbours bag of shit something begining with W boiler (Westhoughton? Watson? FIIK) breaking after 4 winters service and not being able to get the bits for it. Mind you I do think he gets right rotally shafted at times, like the time the roofer charged him £30 a tile to replace some broken ones "because he had to get them from a specialist in Bolton because they dont make them any more" Whereas I went a couple of miles down the road to a roofing supplies place in Leyland and paid about £3 a tile - I mean FFS its just Marley tiles, nothing special - though I did get grey ones and they should have been brown (after 30 years they all look grey). He also got bum raped with a bllke wearing a condom covered in glue and sand over his flu for the gas fire "oh, no its not safe that, you need a brand new one installing at a cost of £700" - I got mine surveyed when considering a new fire and the bloke said "yup, thats fine" I mean how much decay can a concrete pre cast thing just lashed to a Redifussion gas fire actually achieve in 30 years?

Anyway, where was I?

[Way2go]

No, I wasn't advocating these these fragile complicated new things. If you get your boiler changed to one of these then you have to replace all your radiators too, because any weakness will blast out under the pressurised water system.
I still have a conventional floor standing 80,000btu boiler with a pair of 25mm pipes feeding an indirect cylinder (via Gravity) and a second smaller pair of pipes pumped on the radiator circuit. It might use more gas than the newer fangled stuff but it's a reliable system.

[Fish_Botherer]

It might use more gas than the newer fangled stuff but it's a reliable system.

Sounds a bit like the issues are similar to a mechanical-pump diesel versus a high pressure electronically-controlled one....

[Vanny]

Worcester-Bosch is the way i will be buying by the look of things, its standard fitment for British Gas these days.

[Philhod]

Worcester Bosch is the way to go for any type of boiler and FTW. My next door neighbour is a manager with them.

That said Baxi and Glow worm are still good gear and a lot cheaper

Sounds like your mum's boiler stat has deceased FT. If it's an old heat exchanger one a plumber should be able to modify it to take another type if you can't get the original.

There's nothing wrong with these more modern boilers, mechanically and structurally they are in some ways superior to the earlier type. The big worry (for me anyway) is as Mr fish disturber said
Electronic Control systems. In other words something I can't fix. Even the programmer confuses me.
I've just gone onto a new tariff with British Gas, so I will have to read the book so that I can get the best out of it by programming it properly

W2g said something about pressurised water systems. Never seen one of those, what's the purpose of that then???????????????

[charlie]

ive got a ferrolli that been faultless for the last 12 years

and still going strong

he said crossin his fingers

[Way2go]

W2g said something about pressurised water systems. Never seen one of those, what's the purpose of that then???????????????

The central heating circuit is pumped as normal commanded by the Roomstat but the water in the rad circuit when filled and bled is pressurised by the water-mains to about 1.5 bar before the filling tap is turned off. To allow this to happen there is a pressure sphere in the circuit that starts out empty but the air inside is squashed under the water pressure and so maintains system pressure when the fill tap is turned off. With this approach no header/expansion tank is needed and the system remains closed in operation as any thermal expansion of the water is also catered for by the sphere.

[Way2go]

PS: Pressure sphere is a similar idea I guess to the Accumulator sphere of the BX except the dividing membrane and nitrogen is not needed in this case.

[Philhod]

Ah I see. (said the blind man). Very clever !... never come up against one of those.

Will go on the net to check it out. Sounds more thermally efficient.

[Vanny]

Get electric storage heaters and an economy 7 meter, then never turn them on. Worked for me for the last 6 months, my gas bill for the last year has been £3.40!

[Way2go]

Here you go Phil, just had a look myself:

http://britishgas.home-maintenance.info ... g-systems/

And showing the difference between open vented and sealed, including diagrams:

http://diydata.com/planning/central_heating/boiler.php

[Philhod]

WARNING !!! The last link you put in there, W2G , came up with a link to a slimming regime
Like a twat I clicked on it and, a bit later my system told me I had a worm called OPNIS.
and my spyware just took an hour to get shut of it.
I havn't been on anything else so I suspect that. If anyone else has looked at that then do a scan!