which are the best heat exchangers in modern boilers

[mike_s]

Interested in discussing which you think are the best and why?
Stainless seem to have the best reputation but are modern silicone/cast alliminium heat exchangers really inferior?

I was at a Main course last week and they basically said the Mains are the same as the Baxi's and Pottertons except for the cast alliminium heat exchanger rather than the stainless steel as its a cheaper boiler.

Worcester use silicone-alluminium heat exchangers even in their top end boilers. Is this because they are lighter and more efficient or do people think they really will be troublesome in the future?

Just comparing boilers out there that we may install and in the future and interested in the make up of them to help me make my decision, trying to see past the marketing.

 

[stevetheplumber]

alumillium heat exchangers definately aint light personally i think the stainless will prove to be the best in the long run and easier to change if the do fail

 

[Billy Bob Bob]

stainless will last, aluminium silicate is already failing in certain brands

 

[mike_s]

oh I just assumed they were lighter seeing as the Worcesters are very light. Fitted hundereds but cost a lot more than the Mains have been such good value and more reliable so we now fit these in most cases.

 

[Billy Bob Bob]

fact i have never replaced a stainless steel heat exchanger in a duotec they are bullet proof,tbh only heard of one ali in a main failing, aluminium silicate recuperators( god,thats a mouthful) in the performa/105 etc will fail if the systems dirty or ferroquest has been used ali ideal and ariston fail like fun,forever finding bits of worcesters in the trap

 

[mike_s]

yep I find that in the trap with worcesters too though not seen them fail in the modern boilers, will price up baxi's, cheers.

 

[Billy Bob Bob]

yep I find that in the trap with worcesters too though not seen them fail in the modern boilers, will price up baxi's, cheers.

dont forget potterton gold and heat max combis/system boilers are the same as a duotec though normally cheaper

 

[Dai.14]

Worcester offer a 10yr warranty on their heat exchangers which is something that I am not aware that any other manufacturer offers regardless of the material used in it's construction.

 

[Billy Bob Bob]

intergas do

 

[Billy Bob Bob]

do we have anything on worcesters heat exchanger warranty?

 

[Dai.14]

Just seems strange to me that many people view stainless steel as being a superior product but the manufacturer's will not support this with a manufacturer's warranty.

 

[Billy Bob Bob]

baxi give 5 years on the platinum 50 i have fitted no heat exchanger issues( all around 5 year old ) no deposits in the trap,it has been known for worcesters ali silicate to fail,but it does depend on system water quality this is one big factor in aluminium silicate failing so like everything if its installed well in the first place.....,but i have never seen a stainless fail,seen loads of ali in some cases every things been done correctly

 

[Dai.14]

Deposits in the trap are generally from the manufacturing stage where the heat exchanger is cast.

Anything mechanical will fail....just nice to have the back up of a manufacturer's warranty of 10 years. Can be a good sales pitch to the customer.

 

[Billy Bob Bob]

with a worcester it wont matter it will have wet its self long before then when the plastics and o rings go awol LOL no i should not be LOLING i will probably be sticking them back together DAMN

 

[Blackcatgas]

Viessmann, in 20yrs they have never had a warrenty claim for a failed heat ex, but then Iam only going on my exp and the propaganda that the sales rep fills you with.

 

[tamz]

just nice to have the back up of a manufacturer's warranty of 10 years. Can be a good sales pitch to the customer.

As usual with most extended guarantees it comes with a lot of get outs with probably the hardest one to meet being "must be designed for a 20º drop". Very rarely achievable on a boiler swap using existing rads.

IMO stainless is the better product but i do fit a lot of worcesters usually at the customers request. If they believe the publicity and think worcester are the rolls royce of boilers, who am i to tell them otherwise.

 

[richw]

manufacturers using stainless will always slate ali. manufacturers using ali will always say they are fine. having seen some of the latest generation of boilers starting to cost real money to repair and hearing a life expectancy of 8 to 10 yrs claimed for an average condensing boiler, i think an aluminium heat exchanger should be the least of our worries.

 

[tamz]

That is true Rich! Condensing technology is certainly not about saving money.

 

[richw]

too right tamz. modern boilers are very rarely fit and forget these days and customers dont want to interact with there appliances, topping up, understanding prog stats, weather comp etc. a well maintained cast floor standing boiler was surely a decent investment in hindsight.

 

[tamz]

a well maintained cast floor standing boiler was surely a decent investment in hindsight.

And i talked my old man into swapping his Vulcan Continental (which had only had 2 thermocouples in 30 years and serviced about 3 times) for a Vaillant Ecotec. WHEN it breaks down i WILL be out of pocket and will never hear the end of it

 

[washer]

Aliminium heat exchangers will corrode and and bit's fall off, the manufacturers know this, which is why they are made 30% bigger than needed. Thats why it's important to do a decent service every year, washing out the heat exchanger and trap, of course many arent which causes so many problems. Stainless steel must be pretty bullet prove, apart from the small water ways which block up easily imo.

Think gasman might need to lie down in a dark room and talk to a professional concerning his hatred of worcester, baxi must do brain washing courses!!

 

[mike_s]

I'd like to speak to Worcester to hear why they choose silicone-alliminium and believe it to be better. I'm thinking it can't be that bad or they wouldn't risk their great reputation. Most customers have heard more good about worcester than any other make making them very easy to sell and their after sales is great, we have built up a good, long relationship with them so on seconds thought I would fit one if they wanted a top end boiler or a boiler with larger outputs than the Main range. Time will tell, if we have many more problems we will change but last week we had the Worcester rep repair a boiler 3 years old and out of warranty for nothing so that gives me peace of mind.

Even though we are fitting Worcesters and Mains with these silicone-alliminium heat exchangers, if they start failing then yes we might stop but Worcester and Mains aftersales is excellent which clinches it for me, especially Main who would probably send you a heat exchanger free if one were to fail.