New Boiler

System

We had availlant fitted two weeks ago and its brilliant. I can't believe how much the water pressure has improved and can thorought recommend it

bluesy

All the previous posters are obviously happy with their boilers.

On the question of combi boilers, there are 1 or 2 small points to consider.

If ,for whatever reason, the mains water is off, then you have no water either, whereas with an ordinary boiler[with cylinder] you will have some stored water.
This is not something that would put me off combis,as it is a chance in a million.

The flow rate of the H/W from a combi is less than from a normal tank fed system[although they are improving all the time]

When combi boilers first came on the market ,the flow rates were pathetic--top one reached about 6-7 litres/ minute, now they are double that+

So, if you still have a bath in your home , be patient, it only takes about 5 minutes longer to fill a bath.

I think the government is trying to get most householders to fit condensing boilers[there may be laws to this effect, not sure]

They are more expensive than ordinary combis ,but they run at something like 99.5+% efficient, but are slightly more complicated ,therefore more expensive to repair if they play up.

As one of the previous posters said , if you are fitting the boiler to existing rads etc, unless there has been inhibitor of some sort previously in the system ,it should be flushed out properly.

Odyssy

I'm looking to replace my boiler too, the existing system is 15 years old and while it still works OK the boiler is getting noisy. I looked at combis but we have a power shower and the flow rate required for it seems to be at the very top end of combi output. I have had lots of conflicting advice on what would be the best solution, but what is definite is that from April 2005, ALL new and replacement boilers must be of the condensing type. They are up to 97% efficient if the correct controls and stats are fitted. I have also been told that most of the makers (baxi, worcester, vaillant, ravenheat etc,) are still experiencing some problems with the acidic distillate that these unit produce. Apparently only Gloworm seem to have resolved them, even though condensing boilers have been the norm across Scandinavia and much of europe for over 15 years.
I have been advised (by a plumbers merchant who sells various makes) that if possible I should wait till December/Jan to change as there is much development work still going on, and market forces will come into play making the units cheaper, current trade prices for the units - 30 to 40kw output, are around £750 - £900. This is almost double the cost of a similar output non-condensing combi, (Wickes £499 - £599) but the even greater efficiency should repay the outlay within 3 or 4 years.
It looks like there is going to be a further bonanza for plumbers!

amboy

I run a property mgmt company and approx 80% of the houses have combi boilers, the rest having convential ones with tanks. In my experience I have to spent more time and more importantly, MONEY maintaining the combi boilers, more and more of these boilers are becoming an electrical minefield with cheaply made components that are expensive to replace and like previous posts have said once the combi goes the plumber smells cash.

The conventional systems rarely give me any trouble as they are simple boilers in effect, so much so that when my own combi kept faulting every 2 months I decided to opt for a standard boiler and added a tank for the water.

I chose a boiler made in the UK that has been around for years and has a excellent reputation in the trade IDEAL STANDARD.

As for condensing boilers, no way jose, I relate this at the moment to buying a product that is not tried and tested yet, speak to your plumber and if he will tell you that these things are great in theory but practically not sound. Not yet anyway

System

I am a heating installer and have installed boilers for 28 years.Combi's cost the same today as they did 10 years ago basically because the quality is less as with most appliances today.I've installed hundreds of condensing boilers inclusive of all the major brands,all of them in my past experience have proved unreliable and if not fully serviced annually will break down more frequently than normal boilers.Make sure the manufacturer gives an extended warrantee such as the 3 year warrantee by Alpha boilers.The Glowworm 35kW combi is presently £480.00 & vat at Plumbcenter 0151 647 9901(3 gallons of hot water/minute flowrate)Power flush your system when fitting a new boiler to prevent future problems(takes approx 4 hrs and uses a flushing unit and chemical cleaning agents/typical cost £300 & vat) and please stop complaining we earn a fortune a good and properly qualified plumber/heating engineer(IOP and CORGI registered) is worth paying for.

scouselass

Well the info on condensing boilers appears conflicting, which leaves me in a bit of a quandry.

I too will be getting central heating, and was wanting a combi system and I am inclined towards condensing types due to the fuel savings, and it helps the environment. My interest increased when I was told my local council, in conjuctions with Energy Projects Plus, was offering 40% discount! This was for certain makes only, but Worcester Bosch was on the list. Originally, I too had heard that Valliant was the best.

I am wondering if anyone can post whose had their condensing boiler for longer than 2-3 years? So that there is feedback on the reliability factor. The previous post indicates that 'all of them have proved unreliable if not serviced annually'. (Still can't work out how to do quotes!)

A few questions to paulcolquitt, or anyone else. Is that £300 flushing job something that has to be done annually? Does it have to be done by a Corgi person? This is a charge I had not thought about. I do know that you can buy service plans from the likes of BGas, so can I assume these include flushing maintenance?

And what is the reliability rate of a combi if it is not serviced annually?

System

All boilers must be inspected annually for safety according to manufacturers instructions,condensing boilers also need fully servicing annually otherwise the condensate trap can block and cause faults within the boiler(fan failure etc).This is only my personal experience as a service engineer.Condensing boilers are approx 10%/15% more efficient than standard boilers therefore the average annual bill of £400 will give a saving after deducting standing charge of approx £50 per year.The condensing boiler is at least £200 more expensive to purchase than a standard boiler even with energy efficiency grant and is more expensive to install due to it needing a condensate discharge pipe.They usually have aluminium heat exchangers which interact with other metals in the system and therefore suffer corrosion problems.The system only needs flushing when commisioned not annually.My experience of 3 star cover on the heating system is dont bother unless the system is old and unreliable,invest the money in a savings account and use when needed.Typical 3 star cover is £190 per year,£1900 over 10 years plus accumulated interest £275 equals £2175 over 10 years.This amount would nearly pay for a new system.All central heating engineers should be CORGI registered

Haggy_3

In my experience of having a combi for about 3 years we had to replace the heat exchanger every year (at least £70, just for the part), as it would fur up so badly the water flow would drop to nothing. We also had various leaks, one of which shorted out the main circuit board and meant that needed replacement.

Whereas moving to a house with a standard (much older) conventional system the thing works like clockwork with virtually no attention, for over two years.

The other thing to consider is that with the higher mains pressure if you leave your tap running you'll use proportionately more water (which may affect your water meter bills).

Me I'll wait it out and see what Micro CHP has to offer (also generates electricity from the waste heat - much used in Denmark I believe)

scouselass

Haggy, what make of condensing boiler did you have?

jakey_2

I found that one of the best websites to research any thing to do with boilers and plumbing is http://www.diynot.com/forums/
The forums are excellent.