Water treatment for residential steam boiler

Ted Robinson

NY City admits that its water is corrosive, and very soft. I am having my water tested to evaluate my situation.
Eventually I will have to replace my steam boiler which is being held together with stop-leak; so far, so good. Is there a procedure for treating the corrosive public water so a new heating installation won't rot out? (Due to sodium concerns I don't want to use a water softener for all my house water.)
Just in case I am having electrolysis eating away my copper pipes, would isolating my piping from the water main with a short section of pvc help?? Many thanks.

Christian Egli

Not much to fear from drinking water

Galvanic corrosion on steam systems is generally of little concern. A PVC section would interrupt the electric bridge between dissimilar metals, but you can buy ready-made dielectric unions for that.

Steam boilers suffer from fresh water corrosion. That only lasts as long as the water is fresh. Boil it about once, and it is de-aerated. The lime will have fallen out of it too. This produces slowly increasing amounts of sludge in your boiler.

The best is to hunt down all condensate leaks and steam leaks to minimize the amount of fresh water you use.

The less fresh water, the less sludge, the less need for blow down to remove the sludge. It is a vicious circle because lots of blow down calls for lots of fresh water.

With using juices and powder supplements to treat your water, you then have to carefully monitor your water. There will most likely be more sludge to remove, and more blow downs, and more fresh water, and more problems.

With NY water being very soft, maybe there is not much you need to do. Check your boiler water pH to make sure it is always alkaline. That will greatly limit boiler corrosion.

The next source of corrosion comes from carbonic acid that forms in the condensate. It attacks your return lines. Slowly. It is solved in commercial systems by adding (toxic) amines to the boiler water or sodium silicate. With both you have to keep a very close eye on sludge. The carbonic acid comes from the break down of carbonates in the water we drink. Lime is a calcium carbonate.

The problem is made worse if you use a water softening additive that consists of carbonate such as sodium carbonate.

If the city water is heavily chlorinated, that's bad too, but it comes out of the water real quick. It makes hydrochloric acid which viciously attacks your boiler.

Drink water if you must, but make sure your boiler is not addicted to fresh water.

George_10

We have two new products for home steam systems

You can check them out on our web site www.rhomarwater.com

They are under Residential Steam Boilers.

Both products were designed with small home systems in mind. One is a cleaning product and one is a treatment product.

For further answers to your questons, give me a call at
800-543-5975.

George or Dwight