System PH question.

[Mottie]

I have a 10 rad sealed system with a Vaillant Ecotec plus 418 boiler. Although the system had been powerflushed about 3.5 years ago prior to converting it to a sealed system, before the new boiler was fitted two years ago, I removed all rads and physically flushed them out, added some Sentinel cleaner to the system, ran it for about a week, drained and flushed several times and then when the boiler was fitted I added 1 litre of Sentinel X100.

I've just given my magnetic filter a clean out - no particles came out and system water is crystal clear. I have some litmus paper and checking the PH, it showed a reading of 9. My mains water showed a reading of approx 6.5. Reading the installation manual it says the PH should be between 6.5 and 8.5.

So, how do I get my system to a PH of 7.5? More inhibitor? - I have another 1 litre container of X100 - or shall I drain some system water off and refill with mains water? Or am I just flapping over nothing and should I just leave it alone?

 

[sircerebus666]

You're flapping over nothing

You're the first person I've heard of who tests the pH of their central heating system

https://www.vietec.com/water-treatment

Some toilet reading

 

[Mottie]

Christ! That went on a bit. I better get some deionised water to fill my system.

 

[Madrab]

Meet another one then, plus a number of other chaps that I know, that where I was given the tip. If the system needs bled all the time without leaks then it's a sure way to test if the system has an ally hex and is getting eaten and creating H, without burning it of course. It shows a system that hasn't been flushed properly, as a lot of cleaners are alkaline. Dead quick and easy test.

If you ask any manufacturer, they will tell you it is important, that's why they specify the min and max in their MI, if it wasn't important they wouldn't bother.

A clean, flush and refill/inhibit will sort it out if you're at all worried or you start to notice system corrosion

 

[Mottie]

If the system needs bled all the time without leaks then it's a sure way to test if the system has an ally hex and is getting eaten and creating H, without burning it of course.

That’s given me something else to worry about now! I have a Spirovent air separator fitted to my sealed system so I’d never know if my system was creating Hydrogen would I?

 

[sircerebus666]

By any chance are you a natural born worrier?

 

[Mottie]

By any chance are you a natural born worrier?

Why do you ask that?
Lol. Not really, just that I don’t expect this modern boiler to last anywhere near as long as the 25 year old Potterton it replaced but I’d just like to do everything I can to keep the system protected and clean.

 

[oilhead]

If you aren't losing pressure and have good circulation all through the system, than you don't have a worry. I have customers like you, nothing to do and all day to do it. If you managed to keep a Potterton going for 25 years, then my basic arithmetical assumption is that the boiler will outlast you.

 

[ScottishGasMan]

Depends what 418 you have. slightly older version was stainless and wont be fussed in the slightest, slightly newer one with aluminium heat exchanger will not be happy with it and with the airseperatior may well not show the normal signs of gassing up. Its also something that gets worse over time.

Personally, I wouldnt add another inhibitor to already alkaline water, as most buffer towards slightly alkaline anyway, drain it off fully, refill with fresh water and another bottle of inhibitor and you should be ok, or get a buffer agent and add it to bring it closer to 7.5/8

Sentinel is an approved inhibitor for these (as is adey and fernox) so surprised it would go as alkaline, but there are many variables that can affect these things.

 

[Mottie]

or get a buffer agent and add it to bring it closer to 7.5/8

Thanks. Where would I get a buffer agent from? And does it make a difference to the ph if the water is hot or cold - it was hot when I tested it.

 

[sircerebus666]

It does , but its slight and won't change much if you're using litmus paper

 

[Mottie]

I’ve ordered a digital ph tester from Amazon so I’m going to get an accurate reading before going any further.

 

[oilhead]

I’ve ordered a digital ph tester from Amazon so I’m going to get an accurate reading before going any further.

Like I said;
Nothing to do and all day to do it.

 

[Mottie]

Like I said;
Nothing to do and all day to do it.

What are you talking about, I’ve got plenty to do! Tester is being delivered between 6pm and 10pm tonight. I've already set a chair up in the hall and I’m sitting here browsing the tinternet waiting for the Amazon driver to arrive!

 

[wizbongre]

I’ve ordered a digital ph tester from Amazon so I’m going to get an accurate reading before going any further.

Putting Amazon and accurate in the same sentence suggest you are very optimistic!