How to Flush a Radiant Steam Heater

Flush out the boiler when sediment builds up.

Your home heating system may consist of steam heat radiators, allowing for the entire house to be evenly heated for long periods of time. Yet radiant steam heaters require maintenance so your boiler does not clog due to excess sediment in the tank. This excess sediment causes the boiler to struggle more and eventually burn out. During the winter months when you use the boiler, periodically flush the system to clear out the sediment.

Things You'll Need

• Bucket

Instructions

1. Turn down the thermostat to the boiler. Read the temperature sensor on the boiler if you have one installed, or wait several hours based on the size of the boiler you have. Place the bucket under the drain valve. Open the valve to flush out the buildup of sediment.

2. Dump out the water from the bucket. Continue to flush out the boiler until the water runs clear. Close the valve.

3. Pour fresh water back into the boiler until it reaches the necessary level. Turn up the thermostat to a comfortable level. Check that all radiators are heating properly. Perform this process once a week during the boiler's operating season.

Tips & Warnings

• Steam heat radiators do not need to be flushed. These radiators have valves that automatically bleed the air out.

• Water from the boiler is extremely hot despite turning down the thermostat. Stand at a safe distance when draining out the water. Seek immediate medical assistance if any scalding of the skin occurs.

References

• Old House Journal; How To Take Care of Your Radiators; Dan Holohan
• Pinnacle Inspection Services LLC: Steam Heating Systems

Resources

• The Old House Web: HVAC Hot Water Heating Systems
• Fireye: Pressure and Temperature Sensors; September 2006