Need advice re: Draining hot water boiler system


Old 10-01-12, 12:22 PM
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Need advice re: Draining hot water boiler system

My HVAC repairman showed me a leaking pipe in my hot water boiler system and said a plumber needed to replace it. The plumber said he needed the HVAC person to drain the system before he could replace the pipe. Is this easy to do? Do I need the HVAC person to drain the system or can I do it myself?
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Old 10-01-12, 12:45 PM
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It's straightforward...
1. Turn off power
2. allow the boiler to cool. Maybe overnight, or until cool to touch.

3. there should be a drain valve fitted to the lowest of the piping going to the boiler. it probably has threads on it like a garden hose spigot. hook up a hose and lead it into the drain pocket of your basement and let the pump empty out the water as it fills. if not in the basement, run the hose outside and on a downward slope. if in the basement with no pump in the drain pocket, then you're going to have to get creative with water removal.

4. open the drain valve, move the lever on the boiler safety/relief valve to the upright position - this allows the water side to be vented allowing for it to drain.

after leak repaired, the system needs to be refilled and each zone(s) vented.
Old 10-01-12, 01:17 PM
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Drain water with pump

Do you have a pool or sump pump, you can use them to pump through a hose, if no pump, purchase a small pump that fits to 2 garden hose connections and is powered by a hand drill. If you have a utility sink, you can drain to there rather than outside.

Get an electric drill garden hose pump. Attach to lowest point of system after it has cooled. If this is a hot water furnace system, you will need to loosen at least one air valve near the highest point the plumbing reaches, if radiators, open bleeder valves AFTER SYSTEM IS COLD. Be sure to close all valve prior to putting water back in after repair, bleed out air at every location possible, before adding heat to system.
Old 10-01-12, 02:29 PM
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But before you drain the entire system, examine to see if there are valves which can be closed to isolate the section needing repair. The less fresh water you have to put back in the system, the better, for various reasons I won't go into at this time.

Can you take pics? IN FOCUS, WELL LIGHTED, HIGH RES ones that we can see the leaking pipe and all the other stuff around it? With that we might be able to tell you exactly how to do it. I'm surprised your plumber don't know this stuff...

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