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RobLund

Recently I had to remove three radiators for some repairs. This is a hot water system. I drained the system completely. Other than filling the system by using the vent valves at each radiator, is there anything else I should consider. The boiler was replaced about 6 years ago with a high efficiency unit and has a pump in the boiler for circulation in the system. There is a small tank (bladder?) in the system.

Please advise.

Thanks in advance.

hot_rod

Any time you disturb old steel pipe or iron radiators it is a good idea to flush out and rust, scale, and debris. A good flow out a boiler drain or Webstone type purge valve would help clean out the system. Small bleeders do not allow adequate flow or size to remove dirt.

Some of the high efficiency boilers have tight passage ways in their HX, easily plugged with scale and rust.

Do you have a Y strainer or dirt separator in the system? check and clean them after working on the piping.

RobLund

flow when the system was drained was really excellent. The piping has some sort of oil smell in it and is somewhat black. No y stainer or separator other than an air tank. Boiler was isolated when piping system was drained. When venting the smell of the oil was very apparent.

hot_rod

RobLund said:

flow when the system was drained was really excellent. The piping has some sort of oil smell in it and is somewhat black. No y stainer or separator other than an air tank. Boiler was isolated when piping system was drained. When venting the smell of the oil was very apparent.

It may have had a conditioner chemical at one time?

It is a good idea to run a hydronic clean in the system if the fluid you drained out is dirty, black, smelly. Modern systems with copper, steel, aluminum and or stainless need good quality water.

Simple aerosol kits for cleaning and adding conditioners from Rhomar or Fernox. One kit does about 35 gallons of water. Screw onto a boiler drain or hose connection and pull the trigger

RobLund

The system just smells like some sort of oil with a little bit of a tint to the water. This system was installed in 1928. I am not sure that if it were cleaned that I may be taking away what might be holding it together. Except for the new copper piping that was installed around the new boiler, which is about the size of a large suitcase, the remainder of the system is steel pipe.