Boiler recommendation

+1 for Worc/Bosch & add Vaillant & Baxi for alternative consideration

I installed a Worcester gas combi, can't remember the model, but it was the most powerful wall-hung they did, back in 1992, which only ever had one fault in the 13 years till I moved house (pump). Next place had no gas, so boiler was an oil combi, also Worcester, about 5 years old At the time, and I was there for 5 years, one minor problem in that time requiring new HW flow detector one of the pumps, easily replaced myself. Present house also no gas, I installed a Grant oil combi 4 years ago - perfect so far. My brother in law has a Vallaint gas combi, which has suffered annual breakdowns or leaks virtually every year since the guarantee ran out 6 or 7 years ago...  Latter might have been a rogue boiler, or some other factor so not necessarily a reflection on the make in general, so the more people's experiences you can glean from the better.

Many people complain combis don't suit larger houses because HW isn't enough - one problem is too many installers assess size only on heating requirement - in my experience HW makes greater demands on the boiler, so as well as assessing heating capacity required, assess your desired max HW flow (andlength of time if there's a therml store), and ensure the boiler is powerful enough to supply whichever of HW and CH is the greater demand, which in my experience is invariably HW. Supposedly what would then be nominally an oversized boiler for CH would cause the modern condensing type to operate outside condensing mode and thus be less efficient, however that also depends on radiator sizing and CH water temp, with scope to play there including rate of house heating, but only when designing the whole system.

In the case of DIY, the cost of getting a better system is far less, prof installers usually applying a markup on everything, while too many seem not to understand beyond what is either their direct experience, or more often these days what they may have been taught is 'right' and so people end up with systems that don't satisfy their needs... And re DIY, it is perfectly legal to install yourself, just get a Gas Safe or Corgi or whet aver is flavour of the year registered service engineer to make the actual connecation to the gas supply, check the gas lines and flue, and do the commissioning of the boiler to validate the guarantee.

if you use a combi your showers should have a pressure equalizing valve - cost about £70, and what they do is balance the flows if anything changes pressure on either hot or cold, making the  thermostat's job easier and according to some shower manufacturers prolong the life of their thermostats. I have on 2 showers and haven't noticed even a brief change in temp when anyone flushes a toilet or turns on either a hot or cold tap etc, all that happens is the flowrate changes.

Recently installed the largest capacity Worcester Bosch wall hung and it is excellent so far.

It replaced a 15yo floorstanding Worcester.

G

+1 for Worcester Bosch

I've just had a 28i junior Worcester Bosch boiler and flue,magnetic filter, power flush etc..5 years warranty fitted in a flat I let for around £2300 inc vat

I had a Worcester Bosch Greenstar 25si Combi  fitted three years ago to replace some ancient thing that was already old when I moved into my place in 1997. 

Almost immediately I noticed my gas bills going down, it was - still is - incredibly efficient. The back-up service is brilliant as well.

+1 Vaillant.

I’ve used a Vaillant combi for the last three years without a problem. It’s also a lot quieter than the Worcester it replaced, the front and side panels are sound proofed.

It might be a good idea to investigate the control systems available for Worcester, baxi and Vaillant boilers. With the cost of gas being so high, some form of weather compensation control is a no brainer. This involves monitoring the outside air temperature and reducing the boiler flow temperature as the outside temperature increases. If the boiler return temperature is above 55C, there will be no increased efficiency due to condensing. (A non weather compensated boiler will have a default return temperature above 55C). The boiler efficiencies quoted are probable based on tests carried out at 30C flow and 25C return.

All manufacturers will offer weather compensation control, but some may be overly complicated and not easy to use. Not a good thing if you have non technically minded members in your family.

In saying all that, I have a mechanical boiler clock, wireless programmable thermostat (4 time zones per day) and I do the weather compensation myself.

Viessmann. Recommended by central heating engineer when I was enquiring about Worcester Bosch. Exceptional performance and reliability. Not well known here in the Uk but a huge company from Germany.  

Andy

When I had my boiler replaced about 15 years years ago as part of a house extension I asked for some recommendations and was told Potterton were the 'Mercedes' of boilers, which was enough for me.  It's given sterling service in all the years since.  But recognising that it's usually best to replace these things before they die I've been thinking about a new one so I asked the engineer when he was servicing my boiler earlier this year what he would recommend or buy himself.  He was a fan of Potterton but said he'd recently been impressed by Valient boilers. 

as a gas engineer I would recommend  Worcester or vaillant, personally of the two I find Worcester give better technical help plus some vaillants are really glowworms with a vaillant badge on, but at the end of the day whatever boiler you go for,I would highly recommend you get the system powerflush,ok it's going to cost more upfront but will save you time and money years down the line, pointless putting a new boiler on a old sludges up system, modern boiler just can't cope, bit like using a nail on a naim tonearm

if it was my system I would flush it, ( is your system sealed or open, more inclined to flush it if it's open)but if your happy that the water coming out is sludge free then its up to you , as for filters I use a Adey magnaclean professional 2, which are easy to install and easy to service, a must if your not going to flush

sorry I'm still shock after watching the mighty hammers win, you can get the guy who's installing the boiler to check the water, see what he says, but if you do have a flush its six or seven hours job if done right, hope that helps 

Vaillant are generally considered the best in this country. This takes into consideration the product quality, backup, servicing and spare parts availability. Stainless parts in Valiant v alloy in WB comes to mind too.

Vaillant used to have a problem with a particular diverter valve, but this has been solved (and always was very easy to solve by yourself anyway, due to easy service part & availability.

WB are just behind in quality, but make up for it with clever marketing.

Potterton are cheaply made rubbish.

I'm sure you will be very happy with it. Ours is the 42cdi and is excellent - very quiet and efficient.

G

I'm using the new Naim NAB 360a.   Steve and Paul both helped with the installation, it runs off a separate spur of both electricity and water and has an Ethernet connection - from which I can control all  aspects of heating with the NSteam App.

I am a heating engineer and fit Worcester. The CDI Classic combi is superb. You have made a good choice. Fitted to a clean system with a filter and decent inhibitor it will give you many trouble free years. Just make sure it's serviced annually and the service record signed in the back of the book or warranty will be void.

Serviced annually? What a crock of........

What's wrong with serviced annually?  It costs buttons and keeps you safe.  We service the best part of fifteen thousand every year and it helps me to sleep at night, for the price of a night out its money well spent.