Hot Water heating


  #1  
Old 12-20-01, 01:54 AM
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Hot Water heating

My home is heated by circulating hot water through 1" dia pipes to appear as baseboard heating; fins overlay the pipes to diffuse the heat. Anyway, the important thing is it's circulating hot water with a small (~10 - 15 gal resevoir tank) holding tank in the basement near the water heater. Now my dilemma is, from time to time I hear the water flowing thorugh the pipes, sounds kind of like a valve opened allowing the water to flow. If you can imagine this at 2am it canbe quite annoying. Then, there are instances when it sounds like there are blockages, as if the water is somehow impeded from the earlier described flow.

My concern is - are these sounds normal? Does the system need to be "bled", if so how? It does not appear that there is a pump associated with the system so what would be the mechanism to force the water through the system - air? It is a split level house so the water does rise and fall. The home is about 45 years old.
 
  #2  
Old 12-20-01, 02:27 AM
TheZman
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Hello Frank,

Water flows in hydronic heating systems in one of two ways:

1) Hot water is less dense than colder water and rises naturally. And when the water cools off, as it gives off its heat in the radiators, it is returned to the boiler by gravity. This system was used in much older homes, typically pre-World War II homes with coal fired boilers, and is not as efficient as more "modern" circulator pump systems.

2) The second way is with a circulator pump which is located just before the return pipe at the boiler. It is located there so that the circulator pumps the "colder" water and thereby maximizing the life of the pump motor. This system is found mainly in post-World War II homes and is much more efficent in distributing the heat from the boiler to the radiators.

Hydronic systems do require minimal maintanence to achieve maximum performance and minimize funny noises in the pipes.

In my home, I have both cast iron older radiators and "newer" fin-type convector radiators and both make some creaking noises, due to the metal expanding, as the radiators heat up.

1) Typically, on hydronic systems the radiators should all be bled (of any residual air) once a year.

2) All boilers have expansion tanks to accomodate the increased volume of hot water and to prevent your pipes or boiler from exploding. There exists two types.

i ) If you boiler has a diaphram expansion tank (this type is identified by a single pipe from the boiler going into a small 5 gallon tank, typically) you just need to check the pressure (with a tire gauge) and ensure it is about 10-15 PSI. If the pressure is too low, you can pump it up with a regular tire pump.

ii) If you boiler has an older expansion tank (this tank is about 10-15 gallons and has two pipes going into it. One from the boiler and one going to a drain faucet). This type of tank needs to be drained yearly. With the boiler off, you close valve from the boiler and open up the drain faucet at the other end of the expansion tank and drain all water from it. Then you close the faucet and open up the valve from the boiler. It is normally for the expansion tank to refill half way.

Best Regards

TheZman
 
  #3  
Old 12-20-01, 02:30 AM
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Post .....Several Possibilities

Hello Frank L. Welcome to the Heating and Cooling Appliance forum and the Do-It-Yourself Web Site.

In order for the hot water to circulate thoughout the system, there has to be a water pump {circulating pump} located close to the main hot water system. These pumps are not very large and do not make very much noise, if any.

Locate the pump and determine if the pump is noisey or is making the sounds your hearing. Another possibility could be a one way flow check valve or anti-back flow valve, within the piping system has become defective.

If either type of valve has become defective, it could be causing some water to backflow or be restricting the flow of hot water. Heat from the hot water may also be a contributing factor, effecting the entire system or any part within it.

If the house has more then one thermostat, so each room with one can maintain a different temp. each baseboard unit has a seperate hot water valve. Anyone of which may be causing the problem you described.

Regards & Good Luck
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  #4  
Old 12-20-01, 06:45 AM
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Great feedback, thanks to both and I will take your information and do some checking in my basement. Incidentally, the house has three different thermostats, one for each level.
 
 

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