Biological control for filler station

MatthewPK

I have a filler station attached to my closed loop system. Since this is seasonal and the radiant loops run lower temperature the water in the filler station is stagnant.

Should I be using something else in the filler station? Perhaps I need to add a biocide agent?

EdTheHeaterMan

On a closed system there is no need for bio control in most cases.

If you are using your potable hot water heater for heating both the water you shower with and the floor heat, then stop doing that. There will be bio hazard issues that you don't want to have near you in the shower or the kitchen. Your closed loop system and your Domestic Hot Water (DHW) need to be two separate systems.

What is a filler station?

MatthewPK

https://forum.heatinghelp.com/discussion/comment/1863972#Comment_1863972

My boiler is in a utility room without easy access to make-up water so it's setup with a digital fill station. Specifically the DMF150 https://axiomind.com/axiom_product/dmf150/

This replaces a pressure-regulated valve at the fill port.

So as air is purged or sediment is flushed, or pressure relief valves drip etc the system pressure is maintained.

This water is never heated.

MatthewPK

Also, side note, these are very useful for leak detection because you can easily tell if if it's pumping from its tank into your system.

hot_rod

if it is plain water those fill tanks are open systems. You may need to add a shot of chlorine from time to time

Is it well water or public water?. Well water probably doesn't get chlorinated.

MatthewPK

https://forum.heatinghelp.com/discussion/comment/1863978#Comment_1863978

I filled with municipal water. It's easy enough to add chlorine to it but I wasn't sure if chlorine would cause problems in the system.

Jamie Hall

Chlorine won't be a problem. Chloride — note the spelling difference — would be.

Any set up like that I would want to see either an air gap or a reduced pressure zone backflow preventer separating it from the domestic water supply — whether it's municipal or well.

MatthewPK

Please don't take this the wrong way but info I find online seems to strongly discourage adding chlorine to radiant boiler systems.

Here's Google, for example (I know, I know.. AI...)

Jamie Hall

Ah yes. Google knows everything… don't mind us.

MatthewPK

https://forum.heatinghelp.com/discussion/comment/1864045#Comment_1864045

I know you guys are the pros :) that's why I come here.

Is there anything you suggest I read to learn more about what sort of biocides are safe to use versus not? Is there a particular chlorine product that you like for this use case?

Jamie Hall

I would use a straight chlorine bleach, such as Clorox. BUT. You don't need much. The concentration of bleach you are shooting for is between 1 and 5 mg/l. Now that's not much help, is it? Simple translation: you need (more or less) about 3 parts of liquid bleach to 1,000 parts of water. It's a simple ratio.

So, for example, if your system volume of water is around 20 gallons, you need to add 0.06 gallons — or about 1 cup of bleach. It will need to be mixed thoroughly in the system.

That, incidentally, is also the concentration of chlorine in public drinking water. So if you are on a municipal or other public system, it's already there unless you have aerated the water or distilled it — or have an activated carbon filter.

It will, however, gradually leave an open container. It will NOT leave a closed system, even when heated, but if there is significant organic matter in the water, it will be used up by breaking that down.

hot_rod

a lot of the water providers use chloramine now instead of chlorine it stays in the water longer, for situations like you have.

Put a UV bulb in it. Maybe Axiom should condider that😏

Jamie Hall

Yes, chloramine is very common. Has some real advantages, but… its not something the ordinary Joe can go to a store and buy, and certainly not something to make on site! So… bleach.

I might note in passing that the suggested concentration is a lot lower than a swimming pool. But swimming pools have contamination problems which folks don't like to mention but surely do exist!

MatthewPK

Thanks for the advice, gents!

Should I be concerned about any additives interacting with the chlorine? (Like 8-way or Hercules, etc?)

pecmsg

How often to you add water to this system?

hot_rod

I have not heard of any issues with algae or bacteria growth in those stagnate fill tank systems? Have you?

You might call Axiom directly ask for Kirk, Alan or Ian they would certainly know this by now after all the years of building those systems.

MatthewPK

https://forum.heatinghelp.com/discussion/comment/1864070#Comment_1864070

Never. Only if I need to reconfigure it.

pecmsg

then it’s not a concern