AC Now’s Weblog

The principle that heat rises is the principle of how Baseboard hot water heating systems work. Baseboard Hot Water Heating Systems are becoming more and more common as homeowners begin to recognize the convenience, versatility, and cleanliness of hot water heat. The radiators that bring warmth into the room are installed close to the floor, typically along the baseboard.

 

Hot water is pumped by an electric motor and driven through the house in a series; that is hot water enters the first radiator in the house so that the first radiator is the hottest of any. Heat flows from the surface of that radiator therefore the water that comes out of the exit end of the radiator is a slightly cooled. The water then flows to the next radiator in the baseboard hot water heating system and more heat is reduced from the water released into the room. In a closed baseboard hot water heating system the last room in the system receives the coolest water. The water then goes back to the boiler where it is heated and recirculated again.

 

All the water in a closed system remains in that system. If there is a small leak somewhere in the system, there is a recompense mechanism built in. The main water supply from the house is fed into the circulation system through a pressure regulator so that any lost water is replaced.

 

Since the water is contained entirely within the circulation system, baseboard hot water heating systems may have a problem. Water pressure expands when it is heated. If there were no place for expanding water to go it will build up pressure in the system and eventually blow out a pipefitting. The designers of the systems understand this and created an expansion device within the system. This is normally a large tank installed in the system that contains air. Air can be compressed, while water cannot. When the water expands it moves into the expansion tank and condenses the air. There is also a pressure relief valve installed in the system in the event that the air in the tank leaks out and is replaced with water.

 

Normally the boiler temperature is controlled inside so that heat is available instantly when the room thermostat calls for it. When the room thermostat signals for heat, a signal is sent to the circulation pump, which turns on and the baseboard hot water heating system begins circulating hot water through the house.

 

Sometimes there is an imbalance of temperature from the first radiator in the system to the last. Engineers worked out a solution to this problem by putting a control valve on each of the radiators that can be adjusted so that you can make a smaller amount of water flow through the first radiator, diverting the excess flow around and on to the next radiator in the system. If the flow rates are adjusted properly then the amount of energy coming out of each radiator is equal.

 

Maintenance and troubleshooting tips 

• The major thing that can go wrong with a baseboard water heating system is pump failure. The pump becomes noisy when the bearings in the pump fail. Replacement of the pump is a simple task. The pumps can be removed with little loss of water from the system.

 

• The pump seals and the boiler can develop leaks. The good news is that since the water is enclosed in the system and is not replenished on a regular basis, there isn’t a significant build-up of calcium in the tank the way there is in your hot water tank.

 

·         Air trapped in the baseboard water heating system causes a gurgling sound in the system when the circulator is pumping water. Most systems have a small valve at the high points in the system, which can be bled until all the air is removed and water starts flowing from the valve.

 

·         When the overpressure valve blows, it is because the air is removed from the expansion tank. If there is a leak at the extension of the air tank this is not a normal failure. The leak has to be repaired and the system should be drained until the air is replaced in the tank.

 

·         The radiator units are usually made up of copper tubes with fine sheet metal fins attached. These fins can get dusty and clogged and need to be cleaned with a vacuum cleaner.

 

Calling a technician

When the heat system comes on, you’re able to actually hear water running through the heat pipes—that means you know you have air in the system.  When you have air in the system it’s time to call a furnace technician inspect your heating system. Include the expansion tank and air vent when you have the heating system inspected.

 

If the baseboard hot water heating system appears to be in good condition but heating is inadequate, consider having a service technician pressure test the distribution piping for a period of up to 24 hours. If the pressure drops, the system is leaking. When a leak is detected, have the service technician flush the piping to check for galvanic decomposition.

 

If you are in the Long Island area and need a technician to inspect your system, contact AirNow.  Someone will be happy to assist you.