Cleaning Microbore System Before Fitting New Boiler

[cr0ft]

Hi all,

Just quoting for a boiler replacement job. Was wondering how you guys go about cleaning a micro-bore system that has signs of existing corrosion in the radiators (3 of the 12 rads heating up at the top only). My thought was to take off all the rads, clean them out with mains pressure water from a garden tap and run a cleaning chemical through the system for a week prior to the installation. Drain it down and get the cleaning chemical out when swapping the boiler. Combine this with fitting a magnetic filter on the return to the new boiler.

What do you think? I'd be keen to hear how other people clean these systems.

I have the gas fitter I use who will be supervising me installing the boiler/new gas pipework but I don't really want to hassle him with every detail tbh - I realise he's already giving up a fair bit of time to get me trained up.

 

[hammers4spanner]

why why why do people not quote for full heat installs these days ?

sometimes its just best to start over again

 

[Leo21]

I quote extra for a power flush, and I always fit a filter.

 

[cr0ft]

I'd be happy to quote for a full heating installation but if we can clean the existing one out nicely what's the need? None of the pipework is blocked up fully yet and all rads have flow through them. I'm just after finding out the best way to clean what's there ideally. I've heard that powerflushing microbore is of limited use really so would be interested to hear what people think about the best way to clean what's there.

 

[hammers4spanner]

more money thats the need for starters

rads never last forever either you dontforever patch up rusty cars so why bother with microbore

 

[newcastle phill]

I love these 'I always fit a filter' comments.

Thats perfectly fine if its within the customers budget.

So I will add my 'I always fit a filter if the customer is willing to invest and pay for one - and if they ain't.....they dont get one'

Lol

 

[Rickster123]

I love these 'I always fit a filter' comments.

Thats perfectly fine if its within the customers budget.

So I will add my 'I always fit a filter if the customer is willing to invest and pay for one - and if they ain't.....they dont get one'

Lol

Same applies to flues. You get what you pay for!

 

[cr0ft]

Well I went in at £2,500 including VAT to supply and fit a Viessmann Vitodens 19KW 100-W system boiler. I've allowed £570 plus VAT to supply and fit a magnetic filter, remove all 12 rads and clean them plus leave some system cleaner in for a week before we come back to fit the boiler.

Allowed £825 plus VAT on top of the boiler to run a new gas pipe to the boiler down the outside of the house and replace the existing Ideal Classic (same position). Pressure test existing CH pipework (fix any leaks at additional cost). Converting the system over to a sealed system from open vented too.

Perhaps it was too cheap lol as the guy has texted me back within 10 minutes saying he wants to go ahead.. Have told him that any leaky rads/valves will need to be replaced at extra cost.

I may have it wrong but I think it will be a good earner and most importantly, I'm starting to get my own gas work now and portfolio experience

 

[plumben]

As above it all depends on customers budget so my best case would be
Drain down system, flush through a few times and add cleaner for a week or two
Go back drain down and flush through again see how clean system is
Then maybe take rads off and flush out with mains pressure,
Then fit new boiler and install filter

But if the customers not willing to pay

 

[Rickster123]

Why are you putting in a system boiler and pressurising the microbore?

 

[Leo21]

Well I went in at £2,500 including VAT to supply and fit a Viessmann Vitodens 19KW 100-W system boiler. I've allowed £570 plus VAT to supply and fit a magnetic filter, remove all 12 rads and clean them plus leave some system cleaner in for a week before we come back to fit the boiler.

Allowed £825 plus VAT on top of the boiler to run a new gas pipe to the boiler down the outside of the house and replace the existing Ideal Classic (same position). Pressure test existing CH pipework (fix any leaks at additional cost). Converting the system over to a sealed system from open vented too.

Perhaps it was too cheap lol as the guy has texted me back within 10 minutes saying he wants to go ahead.. Have told him that any leaky rads/valves will need to be replaced at extra cost.

I may have it wrong but I think it will be a good earner and most importantly, I'm starting to get my own gas work now and portfolio experience

Good price, strange way to separate it. Why do you do it that way?

 

[cr0ft]

@APPlumbing, my thoughts where that there are some signs of corrosion in the system already. Open vented systems tend to corrode more than sealed systems so by sealing the system up we remove the opportunity for air to get in assuming it's well looked after moving on (which it will be, I will be doing the servicing). I just prefer sealed systems, overall less hassle than open vented imo.

@Leo21, I'm going to have to drain down the system to remove the cleaning chemical and I'm going to have to drain it down to swap the boiler. My idea was to clean the rads and put in the system cleaner for a week prior to popping back, draining down, swapping the boiler over and running the new gas pipe etc. Whilst I have plenty of plumbing experience I don't have much experience of swapping boilers so always willing to listen to other ideas!

 

[stevetheplumber]

i wouldnt be pressure testing any existing system and i would remove and flush the rads before putting any chemicals in most of the carp is in the rads and you dont want to risk flushing that into the microbore

 

[Best]

I would remove each radiator and setting them upright on blocks of wood outside & flush with mains from outside tap. Then I would turn them each upside down & fill partially from the hose & with someone's help flip the rad over a few times to hit the water into the base & flush again.
The Microbore pipes I would open each valve and flush the pipes after system filled.
Best way, as we know with old filthy systems is new rads & ideally new pipework. Great just lifting the old rads & throwing them outside for a scrap man. IMO

 

[Leo21]

I'd put the cleaner in, change the boiler. Then power flush it out. Theres no way I'd be taking all the rads off, to risky and to labour intensive. We have machines for that, powerf flushers.

 

[plumben]

I'd put the cleaner in, change the boiler. Then power flush it out. Theres no way I'd be taking all the rads off, to risky and to labour intensive. We have machines for that, powerf flushers.

That's alright if you've got a powerflush

 

[Best]

But do Powerflushing machines really work?
By that I mean - do they actually remove nearly all the gunge from base of rads? I would be surprised if they did, - even the better type power flushers with magnetic filters etc.
Common sense says the dirt needs put into suspension if it is to be flushed out. I doubt if most chemicals or hitting rads with rubber mallet or drill attachment will work miracles.
Flushing water through an already full of water radiator will not clean the base of the rad as the water will be a barrier to the flushing process. So obvious I would have thought. I mean, say you had a swimming pool with dirt covering the bottom of the pool and you put a high powered hose at one end of the pool base, - would it move the dirt well while the pool remains full of water, or if it were emptied first?
System drained, empty rads removed & flushed with mains water will do a decent job & chemicals added prior to this probably will also help. If you wanted to avoid removing the rads, then draining the system & mains water flushing each rad circuit in turn will do a better job than if full of water, but not as good as removing rads. It might take 2 men at least half a day to a whole day if an average sized house, but using a power flusher properly will also take ages.
I have a basic power flusher loaned to me & I won't use it as it doesn't clean the rads. It does however, look the part & would bluff people.

 

[cr0ft]

i wouldnt be pressure testing any existing system and i would remove and flush the rads before putting any chemicals in most of the carp is in the rads and you dont want to risk flushing that into the microbore

Yes will definitely be removing the rads first! My understanding is that powerflushing is of very limited effectiveness on a microbore system as you get substantially reduced flow through the system. Hence my thinking to take the rads off and clean them all first. The pipes aren't blocked anywhere as there is still flow through all rads so getting the muck out of the rads and then cleaning each pipe run should give a fairly clean system.

 

[wetdrip]

The main crux of you problem is the microbore.
In order to do this as best, you need to make sure that the particles are in " fine form" ie very small particles, they usually recommened double dosing with a chemical cleaner.

Personally, I'd work out your costings for new larger bore pipe work install and then sit down with the customer for a chat regarding the aforementioned.
That's what I'd do.
If he wishes to stay with the microbore, so be it.
IMHO the rads have go to come off and be flushed through using mains.

 

[Leo21]

Not really sure why everybody is saying the rads need to come off? If the crud is broke down it'll come out like 15mm. In a perfect world, yes all rads of and water ran through rads. But it isn't a perfect world and I personally have to price competively to get jobs. And with a filter on a system my bottom line always looks better than trying to charge many an extra hour on lifting rads.