New boiler, unsure which make to go for.

[Rickyy]

BoostMonkey said:

Rickyy said:

I've no issues with plastic as such. There have been instances with certain manufacturers, where "wet" plastic components have split and caused leaks.

I was just disappointed with the Viessmann, because a lot of people have been raving about them and they seem be of similar quality to much cheaper boilers.

Even Vaillants contain a lot of plastic now.

This thread has made me check the bolier we have, apparetnly a not so good 76% efficient (2005 Worcester Bosch 28 CDi).

I'm quite keen to get a boiler with a integrated water tank so we can run shower/kitchen/bathroom tap at the same time, we have no space for a proper tank.

What would you recommend?

How much floor space do you have? Worcester do a model called a Highflow, it's a floor mounted combi with an internal thermal store. These have very good flow rates for hot water.

I'm pretty sure Vaillant do/did a wall mounted boiler with an integral tank for hot water.

[FiF]

We had exactly the situation that the OP has. Open vented system, header tank in loft, hot water cylinder and pump in airing cupboard, boiler in garage with a balanced flue.

Very easy swap to a vented Vaillant and exhaust up the side of the house. Condensate drain out through the wall and to the drain from the cloakroom. Strictly speaking they wanted to take it through the cloakroom and connect up behind the fitted units, but as had taken great trouble to hide all pipework the last thing wanted was to incur displeasure of er indoors, hence outside routing, decent insulation. Pump overrun cable up through to loft and back down to airing cupboard. Magnaflush system and magnaclean filter fitted.

Apart from a recent worry about possible kettling, which turned out to be nothing, it's been fine. Two years in, the saving on reduced gas consumption plus the BG breakdown insurance no longer being paid has more than covered the whole installation cost even after paying for two annual services. V happy.

[BoostMonkey]

Rickyy said:

How much floor space do you have? Worcester do a model called a Highflow, it's a floor mounted combi with an internal thermal store. These have very good flow rates for hot water.

I'm pretty sure Vaillant do/did a wall mounted boiler with an integral tank for hot water.

Currently 100m2, soon to be 120m2. (3 bed semi).
Keen to get as good a flow of hot water as possible, current flow rate with a combi is good but not the best.

Choices look to be:
ecoTEC Plus combination 937 (15lt capacity) - Quite a small tank
Viessmann - Vitodens 111-W (47lt capacity) - Looks to be the pick I think, but your comments on quality are a concern??

Can't find a wall mounted Worcester with internal tank, highflow looks to be floor mounted?

[Alucidnation]

Rickyy said:

BoostMonkey said:

Rickyy said:

I installed a Viessmann 35kw system boiler last week. It was quite average, with a lot of plastic inside.

It did heat up bloody quick though, time will tell if it proves to be reliable.

Maybe a stupid question, but what is the problem with some of the components inside being plastic?
Do they not last over a certain period of time?

I've no issues with plastic as such. There have been instances with certain manufacturers, where "wet" plastic components have split and caused leaks.

I was just disappointed with the Viessmann, because a lot of people have been raving about them and they seem be of similar quality to much cheaper boilers.

Even Vaillants contain a lot of plastic now.

We kept to a standard ov boiler for now, which can be converted at a later date.

Absolutely silent whilst running, which although the others were quiet, they were nowhere near.

Very happy with it and yes, it heats up in no time.

[Pheo]

If you want the best water flow, especially concurrently, then an unvented cylinder is probably better.

I don't know why you'd go combi and then get one with a tank. More things to go wrong and defeats the purpose. Our tank only looses 1kw/hr per 24 hours anyway, so it's not exactly a big deal!

[Sheepshanks]

I just think a combi with a family is a nonsense anyway - it seems ridiculous that every time anyone needs to wash their hands the whole boiler - pump, fan, gas valve, diverter valve etc have to start up, run for a few seconds and then stop.

It seems counter-intuitive to an engineering mind to do that - imagine starting and stopping a car 20-30+ times per day and moving it a few yards each time. You wouldn't be surprised if it didn't last long.

[moles]

Thats what new cars do though stop at every set of lights and start up again as it saves fuel/cuts co2!.

Edited by moles on Friday 1st May 19:52

[moles]

Plastic parts in boilers are a fault waiting to happen. When new it is ok but after a few years it gets brittle and splits down the seam from when it was manufactured. Obviously this doesn't happen to every plastic manifold but if the equivilent had been made from brass I am certain the failure rate would be zero. Also when working on boilers with loads of plastic you tend to order more parts than you need as you are always thinking at the back of your mind that by taking it apart other brittle sections around it will break as well. (or at least i do) Vaillant have the least amount of plastic of any manufacturer out there on the cheaper model the pro they have a plastic diverter valve a plastic pressure sensor and a plastic hot water sensor everything else is copper,brass or stainless steel/aluminium. Viessmann are expensive to buy but use plastic everywhere and use an all black wiring loom which is really helpful to fault find on especially when the awful design of the boiler enables the loom to be crushed in the chassis if opened/closed too many times. Build quality of them is on par with Ariston imo.

[Alucidnation]

moles said:

Viessmann are expensive to buy but use plastic everywhere and use an all black wiring loom which is really helpful to fault find on especially when the awful design of the boiler enables the loom to be crushed in the chassis if opened/closed too many times. Build quality of them is on par with Ariston imo.

Interesting you say that as it wasn't a lot more expensive than a popular equivalent.

As for the wiring loom, again, I have never noticed an issue with open and closing the doors etc. Perhaps a little more care may be needed.

On a side note, how many have you had to replace plastic parts on?

It seems almost impossible to buy a boiler that doesn't have any these days.

[moles]

Its not me that has crushed the loom in the chassis it is boilers I have been out to that have had other problems (where they have been worked on a lot and the case folded up/down a lot). On Viessmanns they had constant problems with the fan bearing plate sticking which meant that no gas would go through to the burner and give an ignition fault. PCB's go quite a bit, rubber hoses block up easily, loom issues and all wires are colour coded black which makes fault finding and tracing stuff a nightmare. Overall they just feel cheap plastic everywhere I just see no benefit in buying one as they ain't even cheap!. Worcester have had the most issues with plastic splitting they seem to have fixed it now but who knows in 10 years time will it reappear?. On older boilers that used plastic first (i.e. all the cheap junk Ariston, Vokera, Sime, Biasi) they look awful now stains all over the boiler, rusting chassis leaking o rings plastic just doesn't last. A well fitted Vaillant will last 15-25 years easily and I bet they will still make the parts for the ecotecs then as well I just don't see that from other manufacturers.................

[dirkgently]

moles said:

I bet they will still make the parts for the ecotecs then as well I just don't see that from other manufacturers.................

Going by the number of pumps and diverter valves that I have replaced they would be foolish not to.

[moles]

Pumps are fine now they back to grundfoss they don't ever go, I am with you on that the diverter valve is the weakest point in the valiant though. (If the water is clean they are fine generally)

[stolt]

had another plumber round tonight, he fits bosch only. I was discussing about powerflush and he said unless we have cold rads at the bottom which normally denotes sludge in them then he reccomends doing otherwise just stick with a magaflow which he will fit in the airing cupboard upstairs.

whats everyones views on the powerflush. worth doing anyway or just sticking with the magnaflow?

thanks

[moles]

If the system is clean then a waste of time but dirt/sludge is the worst thing you can leave in a system and it will cause no end of trouble to the new boiler if there is any left in there. The maganacleans are good but they don't trap 100% of sludge. Maybe take some rads off downstairs and flush a hose through them see what comes out would be my approach.

[stolt]

moles said:

If the system is clean then a waste of time but dirt/sludge is the worst thing you can leave in a system and it will cause no end of trouble to the new boiler if there is any left in there. The maganacleans are good but they don't trap 100% of sludge. Maybe take some rads off downstairs and flush a hose through them see what comes out would be my approach.

ok cheers, personally it was something i was willing to do but this other plumber put doubt in my head.

dont have to drain down the system do i for that, i can just turn the valves each end and then have a bucket handy..

Edited by stolt on Friday 1st May 23:45

[moles]

Yes as long as the valves hold (easiest way to test if they hold turn off both sides and open the bleed screw if they have held the spirt of water should stop to a trickle then nothing within 5-10 seconds)

[FiF]

https://youtu.be/8zIly6LItzk


I was impressed with the magnacleanse flush. We were advised that power flush sometimes wasn't so good on microbore systems. Certainly the amount of crap that came out was amazing even after we had less than a year earlier done a flush when refitting bathrooms and got a blockage, hence flush to clear out the problem. The water going into the unit was black as ink and clear coming out.

[stolt]

been watching magnaclean demo and powerflushing on youtube for an idea on how it works..

[mattrosersv]

Don't want to hijack thread, but my 7 year old external Oil Worcester Heatslave 25/32 appears to have died a death.

Any suggestions on what model to replace it with? I live near Andover, so if there happen to be any local heating engineer folk on here feel free to PM.

Basically the copper flange for the hot water to heat exchanger started leaking and judging from the appearance inside the boiler had been leaking for some time. This caused the electrics to trip in the house. I did have an plumber out who firstly said I needed a new boiler and then on my suggestion to fix the leak and give it a go he replaced the washer hit the reset button and back to life it came.

Been fine for a month then died again. Opened the case to find the same joint leaking due to a badly pitted flange and the rubber washer installed by the plumber perished I have now fixed the leak and then got a Worcester engineer out who opened the case and he would not even touch it, apparently I need a new boiler.

Now - given water and steam has been sloshing around in the case for a while I would hazard a guess that the issue is electrical so the Controller Box, or PCB (PCB seems to check out OK with multimeter). It all seems a bit defeatist to me to give up on the thing and drop £xK into a new boiler. Problem is I can't find anyone interested in doing a proper diagnostic.

The boiler has done 7 years so I am more than willing to replace it, it just goes against the grain to junk something without knowing what is firkin wrong with it. Am half tempted to have a go myself but don't want to burn house down.. Got as far as failing to get the control box out and can't find any decent instructions anyway so have given up.

Cheers Matt

[rdjohn]

BRISTOL86 said:

Friend of mine is in the trade and swears by the Vaillant EcoTec models as the benchmark for quality vs cost balance.

For the lat 30 years, I have only had Vaillant. That's two boilers. In my view they are the Mercedes Benz of boilers. My current one is 10 years old and has been checked twice and found to be working fine.