Boiler advice

[Barlidge]

Ok so recently moved to new house, don't think the boiler had been serviced since being installed circa 2006 and very quickly it became apparent the boiler (40CDI) was losing pressure every couple of weeks. Have had a plumber who I trust to come and look and he's been very thorough with eliminating everything else before pinpointing a leaky heat exchanger and asking if I want it replacing or go for a new boiler.

First off EV was full of water so he drained it and re pressurised. A couple of weeks later he confirmed EV was still holding pressure and not full of water and then moved on to temporarily put the pressure release pipe into a bucket underneath, nothing collected in there so the feed/return were isolated to eliminate the pipework (I actually did this to save him coming in just to turn 2 valves), after the boiler was still losing pressure I turned the valves back on and there was enough residual pressure in the pipework to bring the boiler back to 1 bar so not pipework leaking.

This morning it's now progressed to the point I can watch the gauge go down in about 40 seconds and hear the water running straight out through the condensate pipe.

So without doubting my plumber or my own observations my question is this - Is there anything else that it could be that hasn't already been tested?

Being fairly sure the answer to the first question will be a no the next two questions are - (1) Is it worth just replacing the heat exchanger on a boiler of that age or a false economy? (2) Again assuming that answer will be go for new then which brand - my gut is to go for Vaillant but I have no experience of different brands.

Its a combi serving soon to be 6 Beds, 8 people, 1 bathroom, 1 ensuite and 1 WC. 1 last thing, I may want to fit a water softener at some stage so would be good if its compatible or would I have to make sure the filling loop is fed by unsoftened water?

Apologies for the long post

 

[hunter27]

It sounds like your heating engineer has done everything correctly without throwing parts at it like an expansion vessel or a new PRV.

If you can see and hear it leaking into the condensate when the boiler isn't running it must be the heat exchanger leaking internally. I guess it's a Worcester Bosch 40CDI and this is not too rare a fault, we changed one about a year ago that was fortunately still just within it's 10 year guarantee period, it was Worcester who told us that it was still just under warranty when we checked with them.
I think most heating engineers would agree that W/Bosch generally have the best back up service of all the gas boiler manufacturers but I am not to keen on the amount of plastic parts on them.

I opted for a Vaillant around 6 years ago for my house due to their boilers having less plastic parts in them and a stainless steel h/ex rather than an aluminium one like W/Bosch but have so far been disappointed that they have had to replaced the h/ex and the expansion vessel under warranty within the first 3 years.

If you use a accredited W/B installer and he also fits a W/B filter you should get a 10year guarantee on most of their range.

Water isn't a problem in this area but I believe the system should be filled with un softened water.

 

[Kayos]

Heat cell on one of those is £600 plus fitting plus vat, then the rest of it is 12 years old

New boiler if it was me

 

[Barlidge]

It sounds like your heating engineer has done everything correctly without throwing parts at it like an expansion vessel or a new PRV.

Yeah he's a good guy and has been both thorough and methodical, obviously I will be getting his recommendations as I'd like him to fit it also but wanted to do a little research before going through the options with him so I can at least ask educated questions

 

[Barlidge]

Just thought of something else - I'd also like a better programmer - being an IT orientated person my wishlist would be

The ability to log on to a web page to change the programming (lazy much).
7 day programmer with different temps at different times.
Some usage history like when it calling for heat and the time its takes to get to temperature etc, ideally accessible from the webpage as in the first one

 

[Kayos]

Just thought of something else - I'd also like a better programmer - being an IT orientated person my wishlist would be

The ability to log on to a web page to change the programming (lazy much).
7 day programmer with different temps at different times.
Some usage history like when it calling for heat and the time its takes to get to temperature etc, ideally accessible from the webpage as in the first one

Nest, nothing comes close for a tech person

 

[Kayos]

I must agree.Vaillant are the best.You buy cheap you pay twice!

Ask @bigegg how good vaillant are....

They dont age well in my experience

 

[Kayos]

I suppose withany old boiler,they don`t last forever.Here we go.

No, vaillants seem to fall to pieces at 5 to 7 years old, surprising as when I fitted them they seemed solid but they just dont age well

 

[gaz1]

its the british boilers that dont age well never have done

ours is knocking on its got to be 20 years old and still running is the top of range boiler though
parts replaced
pump, prv valve, pressure guage, expansion tank, thermostat

though has been serviced yearly

also left on full bore by the fitter to just one radiator I hit the roof as i know it will boil the boiler changed it then had full heating to rest of house
was fitted by homeserve at the time on the grant

 

[mangocrazy]

I've been persuaded to go with an Intergas combi boiler by the guy who has serviced my old Keston boiler for the last 18 years. Their big selling point is no diverter valve in their combi range.

 

[Alan Reynolds]

My Potterton Kingfisher is over 30 years old. Never been serviced and has sat enclosed under the stairs since I installed my central heating system. I had never done any plumbing or gas fitting but it was passed by BG after a couple of arguments about venting through the floor and lack of my CORGI qualifications, which I won. My plumber friend recently tested its emissions out of curiosity and it was spot on.

 

[Kayos]

I've been persuaded to go with an Intergas combi boiler by the guy who has serviced my old Keston boiler for the last 18 years. Their big selling point is no diverter valve in their combi range.

Only 6 moving parts or something, and something like a 6 week lead time on any spares

Good luck, interesting concept, I’ve never fitted one but those that do seem to love them

 

[julianf]

How come gas boilers are so rubbish?

Most oil boilers just go on and on for decades. To me, they seem more complex too?

 

[Kayos]

How come gas boilers are so rubbish?

Most oil boilers just go on and on for decades. To me, they seem more complex too?

Because people dont look after them until they break, if they were serviced properly a modern combi will last 20+ years

Instead we get calls saying "Boiler needs an urgent service" but what they actually mean is it hasn't been touched for 10 years but I think a service will fix it. First question I ask is "does it work?" Then tell the customer I'm going to fully test it before I touch it

 

[gaz1]

get a call saying boiler has stopped working can you come now and fix it, im cold

many dont want to wait its now or i will go elsewhere!

you would be surprised on how many say no bodys been in a boiler but you can tell straight away

you start looking at the job

diverter valve gummed up to eyeballs
heat exchanger blocked or leaking
expansion tank failed
someones been in the burner and not fitted another 10.00 ring seal

owner: what so high im not paying that its expensive .......

im sorry its the parts or a new boiler

a prime example

 

[maz0]

How come gas boilers are so rubbish?

Most oil boilers just go on and on for decades. To me, they seem more complex too?

Modern day manufacturing is my guess. They need them to meet modern day standards of efficiency, both in fuel use and heat transfer/losses. They build them with such tight tolerances that there is such little room for error. Find a modern day heat exchanger, cut it open and see how tightly its built. Put this new fancy boiler into an older radiator system, which is usually the case and now you have a ticking time bomb with all that sludge and scale waiting to hit the boiler. Even getting your system powerflushed is rarely enough, it just doesn’t get all the crap out.

Wouldnt envy be a heating engineer these days!

 

[HughF]

I'd suggest a beeston COF domestic It will heat 500ltrs of uninsulated buffer tank to 70 degrees on one hod of anthracite...



No moving parts apart from the flue damper and the front door...

In all seriousness, it's a right pain that a modern combi seems to have such a low design lifespan, I just don't get why something that burns such a clean fuel can have such a low lifespan. My wife's baxi Bermuda was installed in '86, still going strong, no moving parts. I think we'll keep it until the heat exchanger splits.

 

[Craig-SM]

@Barlidge I had the same problem with our Worcester Bosch from new. As it was under warranty the heat exchanger and PRVs were changed all to no avail. They determined the leaks were from the central heating pipe work even though we couldn’t find any such leaks.
We binned off British Gas who had installed the boiler, maintained and repaired it. We went with a local guy who straight away said it was the expansion tank but it was expensive to replace as it required a lot of labour to virtually strip the boiler to replace this one part and instead suggested an external tank, which is the red vessel in the pic. No pressure loss since.

 

[winchman]

Ours lost pressure and it took ages to find the back plate you fit to the wall had a tiny weep on one joint

 

[maz0]

I'd suggest a beeston COF domestic It will heat 500ltrs of uninsulated buffer tank to 70 degrees on one hod of anthracite...

View attachment 192196

No moving parts apart from the flue damper and the front door...

In all seriousness, it's a right pain that a modern combi seems to have such a low design lifespan, I just don't get why something that burns such a clean fuel can have such a low lifespan. My wife's baxi Bermuda was installed in '86, still going strong, no moving parts. I think we'll keep it until the heat exchanger splits.

I lived in Aus for a few months with a cousin in the outback, hot water being supplied by something similar to what you posted. He thought it was a chore to get going but I enjoyed the process of preparing the kindling at night and getting up early to get the water tank up to temperature for everyone to have a shower, there was something very dependable and enjoyable about having that routine. Not saying its better than a fully functioning modern combi, just different. I wouldnt be overly concerned about having to live that way again if it ever came to it.