Boiler Water Testing

[RP1]

Hi All,

Found this forum while searching to troubleshoot a problem I am having with my heating system and hope somebody can point me in the right direction.

I have a closed loop hydronic system and recently started developing leaks in the steel holding tank. I discovered the pH in the system was around 6.3. Major freakout commenced.

I did an initial lye treatment to get the pH up to around 8 and then replaced the holding tank. I lost a lot of the water in the system when I replaced the tank so now I am working on getting the pH adjusted back up. So far I have not added any corrosion inhibitor back yet.

I tested the feed water and it is at a 7.3 pH so I am at a loss to explain the pH of the system water. The feed water comes from a well that has consistently tested negative for bacteria but as far as I know they only test for coliform.

I would like to have the water tested for biologic activity that may be contributing to the pH drop. I read somewhere that bio activity can lower the pH but am not sure about this.

Question #1 is are there any online labs that you can recommend that are capable to test boiler water? I found lots of places that can test drinking water but not sure they understand if I send them a sample of nasty boiler water what to look for. The local labs that test well water just look for coliform but there could be a lot of other things besides that. Or maybe there is a test I can do myself for bacteria?

Question #2 is do you recommend nitrite or molybdate for corrosion protection? Nitrite solutions seem to be easier to find but if I do have a bacteria problem that may make it worse.

Question #3 is what else should I be testing for besides pH, conductivity and corrosion inhibitor concentration?

Thanks in advance for any tips or advice!
RP

 

[maple1]

(broken link removed)

I think that is the one I have seen recommended on here before - someone please correct me if I'm wrong.

 

[TonyVideo]

Having had aquariums for years and deal with PH if you have water that is low in KH or carbonate hardness it will cause easy swings in the PH. You can buy kH test strips. You can buffer this once you get the PH set to the level you want you need to add a buffer. You can buy KH buffers pretty cheap or make your own. Then monitor the kH as well and when it starts dropping add more buffer. This will maintain your PH at a particular level. Hot tubs operate in the same way to maintain PH at a set point by adding buffers or increasing the carbonate hardness.