Cleaning a Central Heating System

[DIYWell]

Big 20 year old condensing gas boiler connected to 40+ radiators over 4 storeys, open system, and the heating system hasn't been cleaned in many many years. Had a rad changed and noticed a ton of black sludge in it when I had a play around. Heating engineer recommended having a couple of 28mm magnetic filters fitted in parallel (eg Fernox TF1), a big drain valve fitted (existing ones are tiny 10mm ones), a chemical cleanse, and final top up with inhibitor. Reckoned it was a 1 day job to do that. He was against power flushing so many rads since it would easily be a 2 day job. All sounds sensible to me.

As it's way past my DIY skills I'm going to get a couple of quotes. Is there anything else I should look out for? Any particular chemicals I should hope to hear mentioned in terms of "chemical cleanse"? Is the process really that simple?

 

[Dan Robinson]

Fernox tf1 are crap.

 

[muggles]

If you're going to get a job done,get it done properly. Yes, a powerflush probably will take two days, and it'll need a commercial-size flushing machine too, but it's going to be a whole lot more effective than your man's one-day "chemical cleanse", which on a system that size is going to be next to useless

Fernox TF1 are pretty rubbish. What size is the pipework coming from the boiler? I suspect you'd be much better off with one of these

 

[DIYWell]

Fernox tf1 are crap.

Ok, so if in your opinion they're crap, what would you recommend?

 

[DIYWell]

If you're going to get a job done,get it done properly. Yes, a powerflush probably will take two days, and it'll need a commercial-size flushing machine too, but it's going to be a whole lot more effective than your man's one-day "chemical cleanse", which on a system that size is going to be next to useless

Fernox TF1 are pretty rubbish. What size is the pipework coming from the boiler? I suspect you'd be much better off with one of these

Well he was talking one day to do the install, not to cleanse in one day. That would be a bit silly wouldn't it.

Two Fernox type things, £200, your big beast, £500 so a big price difference there as soon as you go commercial. Also commercial filters have a far poorer guarantee than their smaller cousins.

 

[Dan Robinson]

Either the Adey unit or a Spirotech unit. It you haven't given any useful information on the system.

 

[Agile]

It s very difficult to make judgements on heating systems we have not seen.

Whilst power flushing done PROPERLY will take about two days and do a good job at cleaning, it may not be the best option.

Chemical cleaning, done like power flushing, one rad at a time, will give pretty good results too. You will see that Adey suggest that with their PowerCleanse.

But if none of the rads have cold spots at the bottom in the middle, then I would expect it may not be that bad and that power flushing is not essential.

If that is the case then I would suggest that it will probably be sufficient to fit one or two magnetic filters and dose the system with the correct volume of cleaning chemical. I would be expecting 4 litres of Sentinel X400 left in the system for about 4-5 weeks during the heating season when heating is going to be used for several hours a day.

During this time the filters need to be cleaned every couple of days at first and then according to the amount of dirt collected.

After the cleaning period the system will need to be completely drained, given at least one clean water flush and then refilled and have 4 litres of X100 added.

What is your boiler type and model?

Tony

 

[DIYWell]

Either the Adey unit or a Spirotech unit. It you haven't given any useful information on the system.

Thanks. I'm a user just after some guidance, not a heating engineer. I've no idea what "useful information" I can give to help things along unless I'm asked.

 

[Dan Robinson]

Pipe size and material would be a start. One pipe or two pipe?

Rad material?

Low loss header?

We're professionals, not psychics.

 

[DIYWell]

It s very difficult to make judgements on heating systems we have not seen.

Whilst power flushing done PROPERLY will take about two days and do a good job at cleaning, it may not be the best option.

Chemical cleaning, done like power flushing, one rad at a time, will give pretty good results too.

But if none of the rads have cold spots at the bottom in the middle, then I would expect it may not be that bad and that power flushing is not essential.

If that is the case then I would suggest that it will probably be sufficient to fit one or two magnetic filters and dose the system with the correct volume of cleaning chemical. I would be expecting 4 litres of Sentinel X400 left in the system for about 4-5 weeks during the heating season when its all going to be used for several hours a day.

During this time the filters need to be cleaned every couple of days at first and then according to the amount of dirt collected.

After the cleaning period the system will need to be completely drained, given at least one clean water flush and then refilled and have 4 litres of X100 added.

What is your boiler type and model?

Tony

Thanks Tony, when you explain it like that, I can see the pros and cons.

The boiler is an Ideal Concord CX240

 

[DIYWell]

Pipe size and material would be a start. One pipe or two pipe?

Copper and steel in the plant room, steel from plant to building, then copper throughout as far as I know. Probably 35-40mm into the building, 15mm at the rads. No idea what you mean by one pipe or two, sorry.

Rad material?

Steel panel.

Low loss header?

No idea what that means so you'll have to explain it.

 

[Steelmasons]

CX 240 won't be a condensing boiler.

 

[muggles]

If you're going to get a job done,get it done properly. Yes, a powerflush probably will take two days, and it'll need a commercial-size flushing machine too, but it's going to be a whole lot more effective than your man's one-day "chemical cleanse", which on a system that size is going to be next to useless

Fernox TF1 are pretty rubbish. What size is the pipework coming from the boiler? I suspect you'd be much better off with one of these

Two Fernox type things, £200, your big beast, £500 so a big price difference there as soon as you go commercial. Also commercial filters have a far poorer guarantee than their smaller cousins.

£200 for something that won't do the job properly, or £500 for something that will. Burn £200 or invest £500 - try to consider the value of things rather than just the price

 

[Dan Robinson]

2 days? Depends on the scale of the problem. Very much doubt it will be doable in a day though.

If you don't know what system components you have, post pictures. Misidentification of the boiler type is a pretty big faux par to start with.

 

[Dan Robinson]

Two Fernox type things, £200, your big beast, £500 so a big price difference there as soon as you go commercial. Also commercial filters have a far poorer guarantee than their smaller cousins.

Cost of everything, value of nothing.

Commercial operates under different law. That extends to consumer law too. Do you think Fernox are going to operate a domestic warranty on a commercial application on a crap product?