New condensing boiler installation - truth or lies

More like 40 years.

Reply to
Doctor Evil
Loading thread data ...

Divert the flue into a chimney stack. That really looks the part.

Reply to
Doctor Evil

A huge thanks to all who replied to my post - many of the comments have been useful in helping me understand some of the issues I had with the visit by BG to look at upgrading my heating system.

This is a long post including an attempt at a summary of what I think I've learnt. Hope it is useful to others as a illustration of my confusions and the problems.

Since BG came to see me my wife found a local plumber and I had also rung a local plumbing comany for a quote. I'm a little nearer a decision but I think the old advice of always get 3 quotes has a big draw back - you get a different story from each one. Not being an expert in heating systems when I'm confronted with differing advice it just lowers your confidence in any of it.

The differences in quotes and advice is vast including (if any are reading I hope my summaries are accurate but if not I either misunderstood or you did not explain it well enough):

o BG suggested keeping my existing system with what seems like a rebadged Glow-worm 30Hxi (thanks Tony). Their quote as BigWallop suggested includes effectively insurance on the new system components and the rest of the remaining system for 3 years (or so I was led to believe - no documentation on that). My shower pump stays so I keep a good output from my shower but still have to put up with the noise from it. Cost £3498 including VAT.

He did not mention possibility of a sealed system or combi boilers.

BG never left my old kitchen where my existing boiler is located, and didn't ask to look at my water cylinder. He did have a laptop, firewire printer and could print out a full quote including colour marketing on the rebadged boiler though.

o plumber 2 (who spent a considerable amount of time with me - what patience) suggested going to a combi boiler (although he would fit a conventional one) - in fact a Worcester Greenstar 440 floor standing combi boiler. He said

a) at 20l/min at 35 degrees C rise, running on mains pressure (subject to testing mains pressure which I'm given to believe is good) it was more than sufficient to match my existing pumped shower and everything else.

b) it would be cheaper to install than keeping my existing system as it was far less components and mostly required ripping (bypassing) existing system out rather than renewing/replacing. Basically, the cold water tank would be bypassed, the cylinder goes, my shower pump goes, electrics are trivial since all that is needed it something to the boiler. I liked the sound of losing my shower pump IF the output at the shower head was as good since the shower pump is noisy.

c) my gas supply to boiler was 15mm and needed to be 22mm. There is no easy way to get a 22mm pipe from the 22mm pipe at the back of my meter to the boiler but it could be run outside (around a 3m run) so long as the pipe was held off the wall.

d) To check the new system would cope/match my existing shower pump I needed to lookup the output from my pump (i've struggles with this as the plate on it quote 3 l/min numbers). Also, I needed to check the spec of the shower valve in my ensuite to ensure it was OK for the new increased standing pressure.

e) we discussed pluming etc and the flue would be routed outside and up the wall to above head height.

f) we discussed reliability of Worcester 440 and he said he had fitted loads, it was good, needed to be serviced once a year and although slightly more involved than a conventional boiler was not time consuming or expensive. On board diagnostics would even detect a leak in my heating system.

g) Mentioning some pipework in concrete floor he was unperturbed, suggesting the increased pressure of my new sealed system was not that high and if existing system was working I'd be OK.

h) I mentioned past experience of combi boilers (over 12 years ago) and he said the worcester 440 was miles ahead of whatever I had then and I would not suffer from excessive reduced flow in winter. He did go on quite a bit about what temperature my shower ran at and how I was mixing alot of cold water with hot to get confortable.

i) he said my existing cylinder (although only 5 years old) was not up to spec since it did not have 2" of insulation (I might have the exact number wrong).

j) all (optional but included in his price) would be in the boiler itself except for a room thermostat. He pointed out the problem with having a room thermstat in the hall where the radiator had a TRV.

k) the worcester 440 had an in built 12l (I think) vessel which had some advantage in the speed in which hot water reached my taps - not sure exactly.

Cost £2600 (for combi boiler worcester 440 floor standing boiler, replacement gas supply to boiler, ripping out / bypassing old system)

- sealed system.

o plumber number 2

quote not received yet but it was for a wall mounting Worcester 3XX (something) 12l/min output at X degrees C rise (have not got the brochure).

o concurred with plumber 1 than cylinder was not up to spec. Also said the hot water feed to my shower pump was too high in the cylinder. Also said the cylninder would be better turned through 90 degrees for easier access to valve - fair enough.

o concurred with plumber 1 re TRV and room therm in same room.

o on business of 22mm gas feed to boiler - some needed it some don't - often plumbers size up from 15 to 22 - a bit wishy washy - I was not certain what was required but if a 22mm pipe was required as with plumber 1 it could be run along outside wall.

o on combi boilers he would do a quote for both but a combi would be more expensive since it required ripping out a lot of stuff - somewhat at odds with plumber 1 who said the exact opposite.

o as with plumber 1 he'd need specs for ensuite shower valve as it might not be up to increased standing pressure if we went combi boiler but the myra shower valve in bathroom was certainly OK (I knew this anyway as some tosser who previously installed shower in bathromm before we moved here plumbed it in to the bath supply where the cold water was mains pressure). When it leaked badly I needed to replace it in a hurry and found I needed a more expensive valve to handle the imbalance. Since then it has been replumbed to the cold tank.

o on combi boilers and my concern over loss of output in winter and at my main ensuite shower he said it would cope so long as someone did not use any water elsewhere in the house (whether cold or hot). He recommended not having a combi boiler.

o servicing required for worcester 3XX was once every 12 to 18 months and would cost around £50.

o room thermostat was required and they would not need to put cables in as it was a (cableless) radio one.

o would quote for a powerflush at £395 which would take the best part of a day as it involved connecting to heating system and flushing through plus connecting to each radiator individually. When I suggested this sounded alot (BG quoted £200) he said if the system had been drained recently and was clean I could just ignore that in the quote. They would have to drain the system twice anyway and lfush it with some agent. He didn't try to sell it to me especially when I said the system had been drained more than 5 times in the last 2 years alone and drained out clean (also all of my radiators except one is brand new).

o mains pressure was good in my area and not a worry.

o it cost them £5 to register the installation with Corgi who would send me something I needed to keep as it would be required when I sold my house.

o gas mains was being updated in my area since it fell off too much (and caused some boilers to shut down) early in the morning when all these new condensing boilers switched on.

What I think is a summary of the "true" bits of advice/information I received from BG, local plumbers and this news group are:

o you have to fit a condensing boiller unless you can amass 1000 pts on a rather difficult to achieve scale. Certainly, a replacement boiler is unlikey to achieve 1000 pts.

o plumning - I'm not going there - it seems a contentious issue.

o when moving to a condensing boiler you need a fully pumped system (no gravity fed hot water) - this is law.

o don't have TRV on the radiator in the same room as a room thermostat

- also avoid rooms with other heat sources - kitchen, rooms with fires etc Ed.

o condensing boilers produce condensate which is slightly acidic and has to have somewhere to drain away.

o some boilers come with bypass valves, some don't. You can't go all TRVs without a bypass valve.

o You need a "boiler interlock" that completely turns off the boiler when the house is hot. Normally this is supplied by the room thermostat. If there is none, another method must be used, such as a flow switch on the heating circuit - thanks Christian/Andy/John.

o some condensing boilers are modulating so instead of a constant power output they adjust to conditions. Minimum outout of boiler is worht looking at.

o There should be electrical bonding from the meter to the main earthing point in the house. The service bonding ought to be done on the consumer side of the meter rather than the supply as used to be the case.

o water cyl>I've had a British Gas man around today to quote for a new condensing

-- Martin J. Evans Wetherby, UK

Reply to
Martin Evans

I Maybe wrong but IIRC all Greenstar boilers are condensing.

Initially before the store of HW in the boiler gives out this is likely true. The usability of the system is likely to be good enough except for high speed bath running.

A wall stat (preferrably programmable) will also be needed to comply with current regs.

And properly sleeved etc. etc. All true.

These are not the end of the world to replace later if they are unsatisfactory.

That avoids the need for a terminal guard but no word on the possible pluming problems and air-space wars.

Fair comment.

See my previous post, however a positive attitude has much to commend it.

Fair comment. This boiler has good performance at the expense of floor space, size and weight.

Possibly true.

The TRV must go. As discussed.

k) the worcester 440 had an in built 12l (I think) vessel which had some

See 'f' and 'a' and 'h'

Probably about right.

Someone who having got a powerflush gadget actually wishes to used only when needed, a rare event, a mark of honesty perhaps?

Actually £4 by phone and £2.50 online. Hardly worth itemising really. As to whether you _really_ will need it when you sell - who knows. It is a legal requirement to register the exchange of a heating appliance with building control it is done with this.

Some condensors are quite sensitive to under-pressure others are very tolerant. Condensors use no more gas and possibly less than non-condensors. Combis tend to place bigger peak demands on the supply network. However if the mains are being fixed in your area what's the problem?

Yep

Yep

Just to be clear . TRVs are needed nearly everywhere. The roomstat is needed somewhere but not with the TRV - in the hall is a good place. remove existing TRV if needed.

Yep

If the boiler says it needs a bypass you must have one TRVs or not.

Yep, but go for the room stat. The alternative gear will not be cheaper, people will be less familiar with it. A programmble room stat can provided an accessible heating control.

I don't think you'll find any fixed power modern boilers condensing or not. The lower minimum the better. Provided the HW heating is OK (combi). If you co for a cylinder then I suggest calculating the heating requirements and then selecting the right sized boiler again lloking at the minimum.

A compliant cylinder is a fast(ish) cylinder.

Both plumbers seem to be saying the right sort of things give or take a few details. The second one wishes to fit a cheaper lighter simpler combi with much less HW output. Still good for shower (but probably not as good as what you have with a pump).

If the wiring from the hall to the boiler is awkward then the £50 extra for a wireless room stat could be worth the extra.

Reply to
Ed Sirett

I have one of these. You only get the 20l/min for a short time, until the internal thermal store is depleted. After that you get about 11/12 l/min (my estimate). I find it half fills a large bath before dropping to the lower rate (you have to turn the taps down otherwise you get cool water).

I don't know what the fuss is all about pluming. It's only water vapour and is rapidly dispersed.

Really? I don't remember mine reporting anything when I had a leak. All I noticed was air in the system and the pressure dropping.

In general combis are good for showers and not so good for baths. YMMV.

Just get rid of the TRV on that radiator.

It has a thermal store internally (that's why it's so big).

Seems a good price. The boiler itself is very expensive.

Maybe you could rip out the old stuff yourself to save some cash.

I doubt that an ordinary combi would be very good at supplying two showers at the same time.

Also check your mains flow rate to make sure that is OK. (>16l/min).

Can go in a dedicated soakaway.

Mark

Reply to
Mark

The Alpha CD50 automatically reduces the water flow, when its substantial store is depleted. The 440 HighFlow will fill an average bath, It still will fill a large bath quick enough as it never runs out of hot water, filling it in with tow stages of flow rate. Also the recovery rate is very quick; a few minutes.

It can make a wall very wet if directed against the wall, or the prevailing wind blows it onto the wall.

The newer models may do. The Greenstar 440 is a very new update.

DON'T GENERALISE. The 440 is a very good combi and will fill an average bath quickly. The Japanese Rinnai multi-points will fill as fast as any unvented cylinder system, belting out the hot water.

About 60 to 70 litres.

He has to fit the condensing version. This can be fitted anywhere and has an integral condensate pump, so there is no excuse not to fit the condensing version. If he doesn't fit the condensing version he is breaking the law.

The 440 has an integrated condensate pump to pump it into a drain that can be way away.

The Greenstar condensing 440 Highflow is a good boiler and you will not be disappointed with it.

Reply to
Doctor Evil

You are righht.

It will fill an average bath quite quickly. It is designed to do so.

And liberates an airing cupboard.

They use a lot less gas than non-condensers, that is why the government has legislated in favour of them.

There are a few around. They are superb for mating with thermal stores.

Part L is not fast, just faster than before.

Reply to
Doctor Evil

Please explain why a small storage tank built in to a boiler which makes it larger than necessary is preferable to a large storage tank which can be situated near anywhere and overcomes the problems of that small one and varying flow rates while filling a bath is such a good idea?

Unless, of course, it's all those leaking joints you manage when attempting plumbing?

Reply to
Dave Plowman (News)

Is that to make room for the second combi? Or perhaps you've never had an airing cupboard?

Reply to
Dave Plowman (News)

You have been told many time, it is clear you lack basic comprehension. And put those DO NOT USE labels back on your gas appliances - the one you took off.

Reply to
Doctor Evil

I don't know, I don't live there. Do you live there? Can you tell us what it is like inside?

Reply to
Doctor Evil

Certainly by you. But then basic comprehension of any problem doesn't seem to be your strong point given your 'one size fits all approach' But then since you live on your own in a one bed flat I'm not surprised.

So you approve of bent CORGI engineers? Even CORGI didn't when I reported him.

Reply to
Dave Plowman (News)

You still need to adjust the taps because the hot/cold mix will now be wrong and you will end up with a cold mix.

BTW, we are not talking about a CD50 here....

Reply to
John Rumm

So suddenly you're aware that not all houses or flats are the same as your ex council one bedroom?

At last.

Reply to
Dave Plowman (News)

The store is *not* substantial. It is 50-something litres.

Small bath.

The second being very slow.

That's rich coming from you

That is not necessarily always true. There may be an exemption based on the points system in some cases. While it is desirable to fit a condensing boiler and in most cases insufficient points will be achieved for exemption, it is a generalisation to say that a condesning product must always be fitted.

Reply to
Andy Hall

You know that, I know that, the OP knows that. Maybe his neighbour doesn't.

Reply to
Ed Sirett

Yes, by me. I have told you many times.

_________________________________________ Usenet Zone Free Binaries Usenet Server More than 120,000 groups Unlimited download

formatting link
to open account

Reply to
Doctor Evil

substantial

I know. But a CD50 does it automatically. You see this adds value to the conversation. They obviously don't do this Essex. The new 440 may do, I haven't looked.

_________________________________________ Usenet Zone Free Binaries Usenet Server More than 120,000 groups Unlimited download

formatting link
to open account

Reply to
Doctor Evil

How is the sink estate today? Hot and bothered. Maybe a riot tonight, if you are lucky.

_________________________________________ Usenet Zone Free Binaries Usenet Server More than 120,000 groups Unlimited download

formatting link
to open account

Reply to
Doctor Evil

About 60. It fills an average bath pronto.

Average bath. You have never seen one, so don't even comment on it.

Overall fill speed quick.

I am avery rich person.

Highly unlikely as the boiler a highly flexible fluing and condensate system.

_________________________________________ Usenet Zone Free Binaries Usenet Server More than 120,000 groups Unlimited download

formatting link
to open account

Reply to
Doctor Evil

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.