Flushing after fitting one radiator?

[Albumen]

Our boiler is leaking, from at least a couple of joints.

Vailant Ecotec Plus 831. 7 (ish) years old.

Boiler man is coming to do repairs soon. He's had a look at it already. He thinks seals/O rings have gone, and thinks due to lack of flushing at install, and/or flux left in system by plumbers since then. One of the plumbers is me.

So he's going to do a power flush too.

There's been a fair bit of work done since the boiler was installed. Mainly by me. I try to do soldered joints, especially with pipework that is going to be inaccessible. Maybe I've been a bit generous with flux? I didn't used to worry, thinking it got washed out, but of course I was thinking of hot and cold, not CH. But it's been drained and refilled umpteen times. And I've got a Spirovent magnetic trap thing on it. Boiler servicers always comment how clean the water is.

Does flux really stay in the system for ever? And could it be rotting O rings for ever?

There's only one of the old radiators left. But I can't get a replacement (it's a curved one, so will need to be made to order) before the boiler man does his flush. It'll be a fairly straightforward retro fit. But there will be a little bit of plumbing to do. Any copper work I'll make up separately, so it would be only the two final joints onto the existing pipework which would, potentially, be adding flux in to the system. Those will be in 15mm.

1. Would that amount of flux cause damage?
2. Would a 'rinse through' flush be enough to remove it, or would I need another power flush?

Many thanks, sorry about long question.

 

[Albumen]

It's a 4 bed semi, 3 reception rooms, 10 radiators (or 12 depending how you count the 3 little ones joined together under the bay in the front room).

 

[ScottishGasMan]

Self cleaning flux is essentially lethal to heating systems if its not flushed out using appropriate chemicals. Simply getting the pipes wet and emptying is just not enough.

A powerflush would only be necessary if the radiators are becoming choked up with black/brown deposits of sludge stopping them from fully heating. Water samples and heat testing would be needed to know what level of flushing is required. If flux, oxygen or galvanic corrosion has started taking a toll on the iron radiators then it may well need a power flush. Heat the CH up and see how evenly all the rads heat up top to bottom and that will be the biggest clue.

The 2nd biggest problem is improper removal of the cleansing chemicals. Some people solder, then add cleanser to the system, but never fully remove it. There for you essentially have cleanser and flux acting on the system, bad for pumps/seals/sensors everything.

If you were to drain water off the boiler, into say a clear clean 2litre empty coke bottle or similar, would the water be clean? would it be colourless? if you looked in from the top could you see the bottom of the bottle? if not then its not flushed enough.


If however the radiators are heating fine, and its simply flux/chemical rather than sludge in the system, powerflushing while benificial, will be overkill, simply fully draining and refilling and running system - then repeating several times before finally filling with water/inhibitor mixed to the correct ratio would suffice. - unless you have drop fed (pipes in walls) radiators in which case a powerflush may be quicker at clearing the water out than individually draining every rad.

 

[Albumen]

Thanks SGM. I've been wondering if a power flush might be unnecessary. As I said, they're all newish radiators, the water looks very clean and there's a magnetic cleaner on the system.

But it has had a lot of work. And as all the work has now been finished (bar this one radiator), I'll probably just let him go ahead.

Would the relatively small amount of flux that I'll use doing these two joints be problematical? I thought of doing a mains water flush. The Spirovent filter I've got is screwed onto a fitting. Take the filter off, and screw on another thing (for want of a better word) and I've got an input/output type thing so I can flush the entire system, both ways if I want.

Or I could use push fit plastic so I'm not adding even the smallest amount of flux back in to the system.

Cheers.

 

[petit_pablo]

Quite simply if your water is clean he's taking the pizz.

Not a bad idea though upselling from a 30 minute job changing a couple of seals to a full days work flushing. He mustn't have much work on.

 

[Agile]

I agree with Pablo!

He is just proposing work which is frankly not necessary.

His justification is that a couple of seals have failed ( perhaps ).

Suppose I suggest that the seals have not failed because of flux? Suppose its just natural decomposition of the rubber material?


One of the main cause of poor DIY flushing is because most don't circulate the water between flushes and just fill and drain. I circulate the water around the system for say 10 minutes to ensure all the dirt and chemicals are well washed around and diluted before the next drain.

Much of the time I use what I call "dynamic flushing" where I fill, circulate and drain at the same time. Kamco have copied that name and method in some of their advice sheets.

Tony

 

[Albumen]

Thanks for the replies everybody.

You're right, he might be suggesting unnecessary work. Though I don't think he's that short of work, it was 3 weeks from seeing the job to him finding a space in his diary to come.

To be fair to him, maybe he's just wondering why a boiler from a supposedly good manufacturer has given us so many problems. This is the second leak he's come to on this, and we've had 2 diverters as well.

I suspect they didn't flush it out when it was installed, and in the first few years it was in I was casual about getting it serviced and putting inhibitor in. I also did a lot of DIY plumbing, with a fair bit of soldering. So the installers, plumbers since then, and I may well have caused problems.

For the past few years I've been scrupulous about cleaning, inhibitor etc. Hopefully with more care from now on the boiler should last.

As we're finally coming to the end of the lifetime's project called 'doing the house', and there's only one rad left to replace, I think I'll go with the flush anyway. Hopefully it can't actually do any damage, can it?

My main concern was how much damage the flux from 2 x 15mm straight joints (or maybe elbows) would do, if it didn't have another power flush afterwards.

Cheers.

 

[Albumen]

We cancelled the power flush. Engineer was due to do the leaks Friday, but called to say parts not arrived at merchants. Leaks got a lot worse over the weekend, so we've booked Vaillant to do the repair, on one of their 'all you can eat' for £288.

Though we've just done the sums. Given that Vaillant do a 7 year warranty, that repair cost x 7 = the cost of a new boiler.

We'll get this repair done, but I think we'll be looking at a new boiler next year. To be honest, we may be to blame.

Looking at what documentation I can find, I think the boiler was fitted in Feb 2006. I think it might not have any sort of service for the first 4 (or even 5) years of its life. And I'm bit sure it was flushed at install. And there's been a lot of work done on the system over the years. With maybe not enough attention paid to flushing, inhibitor etc.

Everything I read tells me modern boilers are sensitive little things.

I think we'll get a new one next year and treat it better.