Recommended mains Gas Boiler

[Topref]

I posted last week that amongst others, British Gas were coming out to price a Boiler replacement and installation of Thermostatic Rad valves. The person who came out from BG was a bit of a waffler but eventually the price of £3700 was printed out for me. As some of you guys pointed out (and what I suspected would be the case) BG was always going to be pricey. At that time, I opted for a conventional condenser Boiler fearing the implication of someone in the shower (mains fed) being hurt if something else drew water from elsewhere. In their quote, the Boiler was priced at £895 and its installation £1597.50.

Anyway, three independant Heating Engineers also came out and two of them expressed deep surprise that the BG rep had not recommended the Hot water cylinder was not changed as the output on their recommended Boiler would "burst" the one currently fitted.

The first Engineer attempted to persuade me that a High Energy Combi would be OK especially after checking the pressure flow of water coming into the property. This obviously meant that the Hot water tank would be removed together with the header tanks in the attic.

To this end, the first and last Engineers have suggested the Worcester Bosch Combi (not sure of the model).

First Engineer priced it (and it's going to be followed up by a printed quote) of "£2000 tops" and, while the system.was drained, he'd connect up "free of charge" a towel rail/radiator in a second bathroom which I am just completing and which already has the flow and return pipework in place.

Second Engineer not in the running and the

Last Engineer verbally quoted £2600 which included the installation of a new towel rail/rad as mentioned above.

I will be deciding sometime Friday what to go for and would like some advice / input from you guys about the various bits of advice as outlined in the above text.

Thanks for reading this.

[DIY]

I am not a plumber so can only describe my experience of having an old gas-fired back boiler replaced recently with a Worcester Bosch Greenstar 24i junior. See

firm I used only installs Worcester Bosch boilers because they find them very reliable and the backup from Worcester Bosch is good if they need to be called out. I got a 'free' 5 year guarantee with mine. Regarding the water pressure issue, that someone in the shower (mains fed) could be hurt if something else drew water from elsewhere; as the new boiler is mains fed you may find that the pressure to the shower will probably drop if someone flushes a toilet/runs hot or cold water elsewhere. The same will probably happen if you are running hot or cold water through a tap, and then someone tries to use the shower - the flow of hot or cold water through a tap will probably reduce, possibly to a trickle. I haven't got a water mains fed electric shower. Our rads are hotter with the new boiler as the system is pressurised, and the plumbers flushed all the crud out.

I am surprised that BG suggested that the current hot water cylinder and header tanks are retained. My fortic cylinder and header tank were removed. Perhaps I shouldn't be surprised, my previous experience of using BG to install gas central heating was a nightmare.

The only criticism I have is the Worcester Bosch timer/temperature control. Ours is wireless, but the wired unit is probably the same; the clock has segments which are set for either day or night time use, with two temperature control dials, one for day and one for night. So, if you have the central heating set to say 6am to 9am, then 5pm to 10pm, and you want the heating on between those times, say over the lunchtime, you use the night time temperature control dial even though it is midday. Strange! Good luck with the installation.

[TheScullster]

"Topref" wrote

Having watched this subject for approx 2 years now and having upgraded my system in a similar way, the consensus seems to be:

If there are a number of people in your house who are likely to want to shower/run baths etc at the same time, then you either need to either:

Retain your hot water cylinder and fit a condensing system (non-combi) boiler. This is what I did but then I have two teenage kids and I'm a bit of a traditionalist. OR Fit a very large combi boiler (i. e. lots of Kw) which will give a flow rate high enough to cope with the simultaneous demand. This may mean a boiler that isn't running quite so efficiently as the larger boilers tend not to modulate down as low as the medium size ones.

There are variations - you could fit a decent size combi and use the heating side for both central heating and cylinder hot water, then use the hot combi supply to feed a dedicated single shower.

HTH

Phil

[Topref]

Further to my initial posting, I've just measured the flow rate and it produced 17 and a half litres in a minute.

[Topref]

Having just read John Rumm's contribution in another thread, I measured the flow from another tap and it came out at 23 LPS. Sounds as if the flow is OK for what I intend having installed.

[Jim Alexander]

Only replying to that point. A half decent thermostatic mixer or electric shower with a stabiliser valve will work well enough to prevent harm in these circusmstances. If that's currently an issue sort the shower out and reconsider the bigger question.

Jim A

[Frank Erskine]

Per second?

Sheesh!

[Topref]

The shower that I have bought and just about to install is a Mira Sport Max

10.8 kw.

[Topref]

OK OK OK - well, on my keyboard, the S is a bit close to the M - ish!!!

[Jim Alexander]

In that case you should not be bothered with harmfull temperature variations and can discount that when comparing proposals.

Jim A

[John Rumm]

Which is an electrically heated shower running from a single cold supply only, not a mixer. So no need to worry (other than about the rather poor shower you get out of these things!)

[stevelup]

I'm wondering why you have bought an electric shower when you are about to get a new high output combination boiler installed?

Steve

[Si]

In message , Topref writes

can I have some of what you're smoking please...

[Si]

or better trade it in for one of these:

[Ed Sirett]

Do _you_ want a combi boiler? If so then go with whoever you want. If you don't then find someone who listens to what you want.

[Topref]

Because we bought the shower some time ago and only now thought about upgrading the boiler. The shower room is recently tiled and all electrics and pipework is in place and hidden. It is also a matter of cost and what we can afford.

[Topref]

We didn't mind either a Combi OR a traditional but we were leaning slightly toward traditional as we fancied keeping our airing cupboard. But after advice from the engineers (not the sales rep from BG) and after comments from this newsgroup, the choice was easier. there was also concern, as outlined in my first post, regarding loss of water pressure.

I am very appreciative of the responses I've had here. well worth asking the question.

[Dave Plowman (News)]

If your existing storage system is satisfactory, changing to a combi is a very expensive option with absolutely no benefits. They are ideal for small flats etc where space for a cylinder etc might be at a premium, or for very low hot water usage.

[geoff]

In message , Topref writes

Litres/second ?

[Topref]

The prices we were quoted for a straight swap of boilers, necessitating a change of hot water cylinder and peripherals was not very much different to going for the combi.