Potterton ProMax Combi - Flush and Clean Sludge (micro-bore system)

[john2k]

I have a micro-bore system on a potterton promax combi he plus boiler. i've got a protection plan with baxi and they send out engineer if something is wrong. recently, the hot water started fluctuating and kept going cold and hot even though that was the only running tap, and also the boiler pressure kept dropping.

So I called Baxi and they sent an engineer, regarding the pressure dropping he said that there is a safety mechanism and because of that the pressure is dropping he topped up that part in the boiler with air with his pump, i have no idea exactly what that is. But in regards to the hot water problem he changed the part in the attached picture and also wrote an advisory note which is also attached in a picture. He said that we need to get the system flushed and cleaned and a filter installed otherwise if sludge related problem happens again they will not fix it.

The problem is my system is a micro-bore system and lots of flushing companies I contacted said that you are not supposed to flush micro-bore systems and if someone agrees to it, it is very risky. So question is, how does one clean and flush out sludge in these systems? The engineer suggested chemically cleaning it.

And the engineer also wrote to install a filter, I will get some quotes but need to know where this filter is supposed to be installed, is it one of those magnetic filters and does it go on the main cold line-in to the boiler? and how often do these filters need to be changed?

 

[terryplumb]

the filter is as you thought magnetic ,and gets fitted on the central heating pipework near the boiler on return side. the part fitted is the domestic hot water heat exchanger ,which when sludged up inside don't work well. chemical cleaning involves adding the cleanser into the c/heating ( radiators) side. you run CH as normal for a week or so, drain and flush and do it again if need be.then add inhibitor into newly introduced water. p.s this is the basic version.

 

[john2k]

the filter is as you thought magnetic ,and gets fitted on the central heating pipework near the boiler on return side. the part fitted is the domestic hot water heat exchanger ,which when sludged up inside don't work well. chemical cleaning involves adding the cleanser into the c/heating ( radiators) side. you run CH as normal for a week or so, drain and flush and do it again if need be.then add inhibitor into newly introduced water. p.s this is the basic version.

Thanks for the reply. So I will need to find a gas safe engineer to install that filter for me. In regards to the chemical cleaning, is it something I can do myself? Problem is I don't have any drain outlets to the outside, every radiator valve seems to have a drain which i might be able to connect a hose pipe to.

 

[terryplumb]

yes to plumber / CH engineer for filter.as not anything to do with gas .you can add chemicals /drain with hose/ flush etc yourself. suppose its down to your diy skills, tools etc and of course a bit of confidence .add to that the know how and your away !!!

 

[john2k]

yes to plumber / CH engineer for filter.as not anything to do with gas .you can add chemicals /drain with hose/ flush etc yourself. suppose its down to your diy skills, tools etc and of course a bit of confidence .add to that the know how and your away !!!

Thanks, I do have a good amount of DIY skills and know how to do compression fittings and copper fittings. I've come across this filter: http://www.ebay.co.uk/itm/262531971764

Seeing as it's not really working with gas, if i turn the boiler off, then completely drain the CH system, I could cut the return pipe and install this right? I am quite confident I can install this item as long as I know what pipe I need to install it to. My only concern is finding the correct pipe, if you or someone can guide me as to which pipe I need to cut and stick this to then that will be great. I can upload a photo of below the boiler later.

 

[terryplumb]

don't know that one, magnaclen is the professionals choice .100 quid at screwfix though. up to you . how is your knowledge on CH ? for instance what's a trv..lockshield..filling loop..flow....return...??? just trying to get a feel for how much help you will need, regards Terry

 

[john2k]

MagnaClean on screwfix looks good. How often does the actual detachable filter part need to be replaced or cleaned? if doing a chemical clean and adding the inhibitor to protect, do you do that before installing this or after installing this? if after, will it not clog up the filter or can the filter be removed and cleaned?

in regards to my knowledge on CH, it is basic. I have replaced radiators and re-located radiators. I know the TRV is the thermostatic valve on the radiator, filling loop is that flexible pipe that has two isolating valves to presurrize the system.

 

[john2k]

I just watched a youtube video by Adey MagnaClean and it seems if i install the MagnaClean then I can add cleaner and protector all through the filter? so saving the hassle of needing to put it through the radiator.

 

[DP]

OP, I would be opting towards magnaclean filter by Addey (spelling might not be correct). Get a good product if you value the warranty.

WRT system cleanse.
I have cleaned microbore systems (did one last week) by flushing and then by chemical route. It has worked for me in the past

If you do not feel confident, remove the radiators one at a time, and clear it out with water and hose plus a rubber mallet (to dislodge the sediment)

 

[JohnD]

the Magnaclean is spectacular at collecting black magnetic sludge, which the chemical cleaners will loosen. It goes on collecting for months, although the amount collected diminishes after the first few weeks. I had good results with Sentinel X400 which is a slow, mild cleaner that you circulate for about 4 weeks.

The early Magnacleans were prone to leak but it is said that the newer ones are better. Once the amount being collected diminishes, you only need to empty them once or twice a year.

If you're going to drain the system and cut a pipe to add the filter, you may as well pour the chemical in through a convenient open pipe. Simpler than forcing it in through a tiny hole.

 

[terryplumb]

the filter collects a lot to begin with
so check / clean daily. as it does its job and system gets cleaner so couple of times a year tops.you can use it to intro chemicals.

 

[terryplumb]

I would do some flushing / cleaning b4 fitting filter.

 

[Hason]

Totally agree with baxi engineer as if he doesn't advise you of the issue, then if fails in the future which it will you can't blame the boiler, not anyone's fault but system issue giving grief, feel for you. But all manufacturers/him serve/domestic and general etc clearly state if any scale/debris/dirty water they won't cover it. Good luck and it shouldn't be an issue cleaning the system, may need to renew manifold if you have one . But engineer will confirm on survey

 

[john2k]

Had a very busy few months so didn't have time to get the filter ordered or installed plus haven't been using the CH over the summer. But now seeing as the cold weather is coming need to get the CH system cleaned and add the inhibitor and possibly install the Adey Magnaclean. There are two magnaclean products on screwfix website

1st: http://www.screwfix.com/p/adey-magnaclean-professional-magnetic-filter-22mm/88402

2nd: http://www.screwfix.com/p/adey-cp1-03-00022-01-2-magnetic-filtration-22mm/49961

Which product is the better option? I assume the £99.99 one?

Also, can someone help me identify which pipe under the boiler I need to cut and install this magnaclean on to? I have attached a pic of the pipework under the boiler. I will drain the CH system using the lowest possible radiator. I have drawn a red arrow on on of the pictures showing which pipe gets hot when CH is on.

 

[EAST61]

The cheaper one is the old version, I'm surprised SF are still selling it. You want the Pro 2. You'll find it for £83 on a popular auction site.

The Magnaclean should be fitted as close as possible to the boiler on the return pipe. Pull out the manual for your boiler and locate the return pipe. Make sure that you leave enough room to lift the cap off the magnaclean for maintenance.

You may also want to double check that your pipes are 22mm to the boiler. Can't quite tell from the pic.