Closed loop boiler fill water

Solid_Fuel_Man

So.... I've discovered that this summer's drought has made my well and every other well yeald much harder water. All the municipalities locally also use well water.. same problem. 

I've tested several sources and found hardness to be in the 12-18 grains range. 

Most boilers recommend 7 grains maximum for the fill. 

I've looked into a fill cart and found it hard to justify. Locally available DM water is $1 a gallon. 

What about rain water, filtered through my jockey pump and 3 micron filter? Its chloride free, soft, and well....free! 

Thoughts? Am I crazy? 

hot_rod

ph is a bit acidic, adding some hydronic conditioner would be a good idea. Yeah you really don’t want that 12-15 gpg
Look at TDS also, seems it varies widely with rain water.

mattmia2

You can make an inexpensive cart with a submersible sump or utility pump, a bucket or sturdy trash can and a deionization filter.

hot_rod

Car and window washers use DI, find them online. If it is just a single fill you can but a cartridge system. This would probably do 80- 100 gallon.
It really depends on the TDS of the water you have. Higher TDS, less gallons out of the cartridges.
If you plan on doing hundreds of gallons, or use water often, a RO system start to become cheaper/ gallon.

To build a cart, start with carbon filters, RO, then DI.
The carbon filter extends the RO membrane, the RO does the heavy lifting before the DI.

Then add some hydronic conditioner to get your Ph boosted, O2 scavenger, film providers, etc.

Typical well and public water seems to run anywhere from 150- 300. Higher TDS in area where a lot of deicer chemicals are getting into water sources, chlorides mainly.

Here are two setup that window washers commonly use. On the left the 3 stage, on the right a resin bed DI. About $1800. vs 250 or so for a resin tank.

Solid_Fuel_Man

The industrial sites which I service (high pressure steam) dont condition their makeup water at all. They all use the same chemical company which uses a closed loop measuring system and inject chemicals automatically. 

I'm using Sentenal X100 as recommended by Weil-McLain at a 1% dose. Total system volume is 95 gallons. As I have a 45 gallon gasification boiler in there as well. 

Solid_Fuel_Man

@hot_rod I looked at those but was hesitant if that was really what I should use. 

I may get one just for this. I've got a full boiler water test kit. I need to get a cheap TDS meter though. I can use my digital multimeter and get a decently close number though. 

hot_rod

Yeah, you can fix some of the problems with hydronic or steam water by adding chemicals. If you fix the water first, the ongoing chemical costs may be lower.
RO rinse water from a carwash would work if you buffer it. I think all the brand name boiler additives are good.Test every few years to assure they are still in good shape.
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HomerJSmith

Well water can work fine for a while until it doesn't. In today's world, water quality is a very, very important issue.

The effects of bad water on a boiler sys comes much later, long after the contractor has left the scene of the crime.