System Chemical Flush Best Practice

[Steve W2]

My first post here, looking for some advice.

I've just had my boiler replaced with a worcester 4000 combi boiler. The engineer put chemical flush and inhibitor in when filling up, ran the raditors hot and then tested using a strip. And has left both in saying this is safe, and standard practice, is this correct?

I questioned this with the original engineer (owner) who again said that it was standard practice and that they would drain the system as part of first service.

 

[Last Plumber]

You can treat a system with cleaner and leave it for a time depending on condition of water (couple of days to a couple of week usually), then flush/drop it out and flush with fresh water + treat with inhibitor. That's one way but I personally have never heard of adding both and leaving them for a year.

 

[Chuck]

You haven't been specific about which products are being used but they will come with manufacturer's instructions, as will the boiler. Whether what's been done is okay or not depends on what these MIs say.

 

[Steve W2]

You haven't been specific about which products are being used but they will come with manufacturer's instructions, as will the boiler. Whether what's been done is okay or not depends on what these MIs say.

Center cleaner and inhibitor on commissioning document. With product code for inhibitor something like 2NH50Jnor but writing is illegible.

Also what does the test strip signify as regards system water quality ?

 

[ShaunCorbs]

Did they drain the cleaner out ?

 

[Steve W2]

Did they drain the cleaner out ?

Engineer said he did drained from system filter after radiators got to temperature, which effectively drained half the system ie upstairs radiators but did not drain further or flush before refilling and then added inhibitor, tested with a strip which was light brown which he said indicated system water was good.

 

[Steve W2]

You can treat a system with cleaner and leave it for a time depending on condition of water (couple of days to a couple of week usually), then flush/drop it out and flush with fresh water + treat with inhibitor. That's one way but I personally have never heard of adding both and leaving them for a year.

The engineer said he did drained from system filter after the radiators got to temperature, which effectively would drain half the system ie upstairs radiators only but did not drain further or flush before refilling and adding inhibitor.

He then tested with a test strip which was light brown which he said indicated water was good. I've tested using litmus paper and central heating water is PH8 which I understand is normal and looks clear.

Is this ok ?

 

[ShaunCorbs]

Sounds ok and ph is good

 

[Last Plumber]

The engineer said he did drained from system filter after the radiators got to temperature, which effectively would drain half the system ie upstairs radiators only but did not drain further or flush before refilling and adding inhibitor.

He then tested with a test strip which was light brown which he said indicated water was good. I've tested using litmus paper and central heating water is PH8 which I understand is normal and looks clear.

Is this ok ?

If the Engineer is happy, the water is clear and pH seems to be OK, I wouldn't worry too much about it but if it bothers you or for peace of mind, use the Fernox system health check.
You send a sample off to their lab and they will analyse it and email you a full report.

 

[Steve W2]

If the Engineer is happy, the water is clear and pH seems to be OK, I wouldn't worry too much about it but if it bothers you or for peace of mind, use the Fernox system health check.
You send a sample off to their lab and they will analyse it and email you a full report.

View attachment 84215

Thanks for the advice, I did see this test advertised but wondered if it would work with Center cleaner and inhibitor products?

 

[Chuck]

Thanks for the advice, I did see this test advertised but wondered if it would work with Center cleaner and inhibitor products?

"Interpretation of the results is based on the samples being representative of the system and treatment being with Fernox products"

Center do a similar test:

Center domestic water test kit | Wolseley

Looking for a Center Water Test Kit CP1-03-00626-CB? Order from Wolseley today - free delivery or click and collect available nationwide.

www.wolseley.co.uk

They're interesting in a geeky sort of way, but not cheap, ca £100.

 

[Last Plumber]

Thanks for the advice, I did see this test advertised but wondered if it would work with Center cleaner and inhibitor products?

It might not tell you anything about other brands of inhibitor and their dose rate but it will tell you whether the water is corrosive and what's in it.

Half fill a jar with system water and drop a mild steel nail in it, give it a day. If there is rust, the system needs inhibitor.

Old fashioned way but it works as it is basic chemistry.

 

[Steve W2]

Thanks for the science suggestion, I have just got back a report from Fernox which confirmed a pH of 7.8 against an 8 which I estimated using litmus paper, they also confirmed it was reasonably clean, although the water is harder (calcium carbonate content) then recommended at 250 compared to a maximum of 226ppm.