Vaillant ecotec plus 415 heating issue

[Nashu77]

There appears to be an awful lot of crud in there, I now wonder if your system is choked up with it?

Hope not, it is just floating on the surface, water inside down looks clean, but from the old radiators it was leaking a huge amount of dark tar like mud. Still have 3 small old radiators down stairs, hallway, kitchen and small bathroom that probably full of gunk.

 

[Harry Bloomfield]

Hope not, it is just floating on the surface, water inside down looks clean, but from the old radiatirs it was leaking a huge amount of dark tar like mud.

It will be clean looking because of the fresh clean water you introduced, but the dark tar from your radiators suggests otherwise.

 

[Nashu77]

So in order to have the heating working normaly what should i do? Drain and flush everything? Or this is another problem besides the boiler pumping problem?

 

[Harry Bloomfield]

So in order to have the heating working normaly what should i do? Drain and flush everything? Or this is another problem besides the boiler pumping problem?

I would drain and flush anyway, thoroughly and until the water runs out clean, then put inhibiter in, but there is no certainly that is you only issue. A matter of working through all of the possible issues which might restrict the circulation.

 

[muggles]

Get everything flushed out but be prepared for the possibility that the boiler is also full of the same gunk. These boilers cannot be properly flushed due to their heat exchanger design - if it's full of the same thick gunk then you'll either need a new heat exchanger or a new boiler

 

[Nashu77]

Thank you so very much for the help.
Is it an easy job to flush? Could i do the flush? I seen there are 2 types, chemical flush and power flush, i wouldn.t like to pay 300 400gbp for the flush to a plumber to find out that i need to change the boiler.

 

[Mottie]

If you need to change the boiler because it’s sludged up, you’ll need a flush (and a filter) to protect the new one.

 

[Harry Bloomfield]

Thank you so very much for the help.
Is it an easy job to flush? Could i do the flush? I seen there are 2 types, chemical flush and power flush, i wouldn.t like to pay 300 400gbp for the flush to a plumber to find out that i need to change the boiler.

Assuming it needs the flush, they will not install a new boiler without insisting on a flush first - so your time will not be wasted in doing a flush. The water passages in modern boilers are much smaller than they used to be and are easily blocked by crud from your system, which is why filters have become so popular.

We cannot tell from descriptions, how badly choked up your system is, all we know for almost certain is that you have an apparent circulation issue, with some level of crud in the system.

Try and work out how your system has been plumbed, find the low points - the low points should be fitted with drain valves. Turn the water off to the F&E tank, attach a hose to the drain(s) and let all the water out. Open bleed valves on the upper floor radiator, then open bleed valves on the lower floor as the system level falls. Some people find it helps to remove radiators and take them outside to give them a separate flush out. Run water in from various places and draining, until the water runs clear.

Some people add chemical flush to the system and run it with that in for a few days before flushing, but your system is not functioning, so all you can do is water flush.

What ever you do, make sure once you have it sorted out and working - Make sure there is proper inhibiter added to the system and a filter. The lack of inhibiter causes the radiators to rust internally and has probably caused your present issues.

 

[Nashu77]

Great post, thank you very much, that is exactly what i will do.
I located downstairs the draining valves, can you please let me know what is the standard hose size as Diameter ?
Want to order one online as i don.t have one in house.

 

[Harry Bloomfield]

Great post, thank you very much, that is exactly what i will do.
I located downstairs the draining valves, can you please let me know what is the standard hose size as Diameter ?
Want to order one online as i don.t have one in house.

I have used a normal, cheap garden hose, which on mine was a little too big, but with a Jubilee clip to tighten it.

 

[muggles]

Thank you so very much for the help.
Is it an easy job to flush? Could i do the flush? I seen there are 2 types, chemical flush and power flush, i wouldn.t like to pay 300 400gbp for the flush to a plumber to find out that i need to change the boiler.

Given how dirty your system is, I'd recommend a full powerflush. A drain and chemical flush just isn't going to do it here I don't think. As others have said, it'll need properly flushing before a new boiler is fitted anyway so this is a good time to do it. It's a condition of both boiler warranties and British Standards that boilers are fitted to a clean system.

 

[jazzflavours]

For what its worth I until a few weeks ago had the same boiler model as yourself, a Vaillant 415 ecotec plus open vent. The video you supplied without doubt shows there is alot of gunk & limescale in your boiler heat exchanger - the sound in the background almost certainly is 'kettling', the noise a boiler makes when there is sludge and limescale in the system supported by the F/E tank pic. The previous observations about doing a power flush to my mind are correct. The Vaillant heat exchangers have narrow tubes which once clogged up cannot be flushed. The analogy I would use are human arteries. My guess is that at some point the boiler was added to an old system that was not power flushed thoroughly illustrated by the fact that you have already had to change two rads. Whenever I decorate a room I drain down the rad for ease of decorating and after replacement I add a dose of sentinel inhibitor to the F/E tank BEFORE turning on the rad valves (TRV's + Lockshield). This keeps the system topped up. In your case if you are going to change the boiler I would drain down the whole system, which I imagine you already have done but take off each radiator and blast it out with a high pressure hose. A powerflush will not get all that gunk out. Ideally change the whole system with boiler and rads but of course that is added expense. I replaced my Vaillant with a Viessman W-100 open vent which has a solid stainless steel heat exchanger with wide channels that are not susceptible to blockages. The new Vaillants are using aluminium heat exchangers..

 

[iateyoubutler]

For what its worth I until a few weeks ago had the same boiler model as yourself, a Vaillant 415 ecotec plus open vent. The video you supplied without doubt shows there is alot of gunk & limescale in your boiler heat exchanger - the sound in the background almost certainly is 'kettling', the noise a boiler makes when there is sludge and limescale in the system supported by the F/E tank pic. The previous observations about doing a power flush to my mind are correct. The Vaillant heat exchangers have narrow tubes which once clogged up cannot be flushed. The analogy I would use are human arteries. My guess is that at some point the boiler was added to an old system that was not power flushed thoroughly illustrated by the fact that you have already had to change two rads. Whenever I decorate a room I drain down the rad for ease of decorating and after replacement I add a dose of sentinel inhibitor to the F/E tank BEFORE turning on the rad valves (TRV's + Lockshield). This keeps the system topped up. In your case if you are going to change the boiler I would drain down the whole system, which I imagine you already have done but take off each radiator and blast it out with a high pressure hose. A powerflush will not get all that gunk out. Ideally change the whole system with boiler and rads but of course that is added expense. I replaced my Vaillant with a Viessman W-100 open vent which has a solid stainless steel heat exchanger with wide channels that are not susceptible to blockages. The new Vaillants are using aluminium heat exchangers..

How did that go Jazz? I too have a 415 which makes this exact same noise, has done for a long time, and although the boiler works the noise is annoying - especially when I have the hot water timed for early in the morning. I want to change it and have shortlisted the exact same Viessmann as you have. How have you found it? Is it quiet compared to the ecocrap?

Thanks, and sorry to sidetrack the original post

 

[jazzflavours]

More than happy to. Yes it's quiet when in operation but so was the Vaillant. The problem lies in adding a boiler to a radiator network that has sludge and metal fragments in it. In that case I'm sure even the Viessman would manifest the same noise issues. That said I'm very happy with my new Viessman open vent - its a neat looking boiler, compact and is located in my kitchen behind a unit door. The controls are simple to use and located on the front as opposed to Vaillant that hide them behind a spring loaded door that can be a fiddle to access. I have the 16KW Vitodens model which replaced the 415 15KW model running 7 rads. Seems well suited to the job. To be fair to Vaillant the reason I changed my boiler which was fitted in 2008 was that I decided to do away with my old fashioned copper indirect cylinder for a Viessman Vitocel direct cylinder which operates under mains pressure. Great pressure now on all the hot water taps in the house without having to bother with water pumps. So I decided I might as well go for a replacement boiler as the whole system had to be drained down anyway. 18 months after I had the Vaillant installed in 2008 I noticed I was getting a rust colored residue coming from the condensate white chamber which was a nuisance but did not affect the operation of the boiler. Also I would sometimes get an Fault pump indicator even though there was nothing wrong with the pump. Just so you know the Viessman condensate outlet is on the rear left of the boiler as oppsed to the rear right with the Vaillant so had to replace a few tiles with my set up rerouting a flex hose. The flue outlet had to be moved a few cms and the flow and return pipes on the Viessman are switched but still on the rear top left of the boiler.
For the record I would encourage anyone reading this to stick with a conventional heat only boiler and avoid combis especially if you live in a hard water area . If you do not wish to convert your loft into a living area the header tanks are not really in the way and do away with many of the faults inherrent in a combi such as scaling up, losing pressure and the integrated expansion vessel which works under alot of pressure and often fails. Hope this helps

 

[iateyoubutler]

Thanks for the reply and info Jazz My system is a bit of a mystery, it originates from the late 1970`s and like yours has 7 rads and a hot water cylinder. When I bought this house 10 years ago it still had the original Ideal Concord boiler that was put in when the house was built - that old battleship worked perfectly, and if it wasn`t for the blue flames showing through the little transparent window on the front then you would know it was even on! Then I wanted new and the Vaillant came along. For 6 months it would take up to 3 hours to get the heating system up to temperature, it just wouldn`t wind itself up, then it just started working for no obvious reason?? Soon after I was getting the famous droning noise that these boilers make, basically meaning that the heat exchanger is blocked, but there is no way it could have been! In between I`ve had numerous lockouts, including the circulation one that you`ve had. The best one (and I forget the code) was to tell me that the contraption had no gas supply!! Over the last couple of years I`ve re-jigged the system, nursed it, power flushed it, chemical treated it to help this boiler and it still makes the same racket as yours did. My system couldn`t be cleaner, it`s been flushed, treated, emptied, re-filled so many times I lose count, the water is crystal clear, all rads are hot evenly, and still the noise. You could put goldfish in the header tank and they would be fine! I had a few different installers in giving me the combi b*llsh*t, and it doesn`t wash. I like the traditional system, and like you I have no problem with having tanks in the roof. I just think mine was a lemon straight out of the box..........