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joethomas
Dec 21, 2006, 12:58 PM
Noise problem - The pump is partly resting on a vibration pad and wooden boards which are on top of a concrete pad. The concrete pad is outside and not attached to the unit. The pump noise is reasonable for about seven months. Then it becomes very loud for several months until the pump wears out and has to be replaced. When you touch the pipe before it enters the floor you can feel the vibrations. You can also feel the vibrations in the pipe in the floor where there is access to it. Rsimplico, I like your pump isolator idea. The pump is currently connected directly to the metal pipe going into the unit. Could this be a big part of the noise/vibration problem in the unit? Also, does the fact the pump is regularly replaced with new ones rule out cavitation and bad bearing issues?

Pumps wearing out frequently problem - It is not a closed system. The hot water is used for both heating and household use. There is a modest looking water softening element attached. Could mineral build up in the open system over many years put the pump under strain (become underpowered)? Would that strain cause it to wear out frequently?

caibuadday post - it is a closed system mineral should not built up too much . Does it sit on any kind of vibration pad?

Rsimplico post -
I just want to clarify, this is a hydronic heating system correct? From what I know of hydronic heating, this could be several things.

It is not out of the question for the heating coils to become clogged, which would need to be acid washed out (I really recommend a hydronic contractor doing this). But caibuadday is correct in that a hydronic heating system is a closed system (or should be), and once the water has been added to the system, corrosion and mineral build-up are not significant, unless a lot of make-up water has to be added (because of a leak). The coils are most prone to clogging because the passages are smaller.

The issue of the pump noise is a little trickier. As mentioned above, it could be mounted directly to the concrete, instead of through rubber isolators. It could also be quieted by using pump isolators, as related in this story: http://www.hpac.com/member/archive/0009war.htm#noise . It could be cavitation in the pump (air coming out of suspension to form bubbles), which can also ruin the pump. It could be a bad bearing in the pump. It could also be that the pipe is rubbing against the floor & framing of the first unit.

If the pump wasn't underpowered when the system was designed and installed, I sincerely doubt it is now.

Original post -
Noisy pipes
Background: On demand hot water is pumped through twenty condo units. Also, each unit has a forced air hot water heating element. The outdoor pump is loud and wears out frequently. The noise and vibration travels up the pipe into the floor of the first unit. The pipes make a lot of noise in the unit.

Question: Is the pump under powered? Has eighteen years of mineral build up in the pipes and heating units caused a problem? What can be done to quiet the noise in the unit?

caibuadday
Dec 21, 2006, 06:45 PM
Noise problem - The pump is partly resting on a vibration pad and wooden boards which are on top of a concrete pad. The concrete pad is outside and not attached to the unit. The pump noise is reasonable for about seven months. Then it becomes very loud for several months until the pump wears out and has to be replaced. When you touch the pipe before it enters the floor you can feel the vibrations. You can also feel the vibrations in the pipe in the floor where there is access to it. Rsimplico, I like your pump isolator idea. The pump is currently connected directly to the metal pipe going into the unit. Could this be a big part of the noise/vibration problem in the unit? Also, does the fact the pump is regularly replaced with new ones rule out cavitation and bad bearing issues?

Pumps wearing out frequently problem - It is not a closed system. The hot water is used for both heating and household use. There is a modest looking water softening element attached. Could mineral build up in the open system over many years put the pump under strain (become underpowered)? Would that strain cause it to wear out frequently?

caibuadday post - it is a closed system mineral should not built up too much . does it sit on any kind of vibration pad?

rsimplico post -
I just want to clarify, this is a hydronic heating system correct? From what I know of hydronic heating, this could be several things.

It is not out of the question for the heating coils to become clogged, which would need to be acid washed out (I really recommend a hydronic contractor doing this). But caibuadday is correct in that a hydronic heating system is a closed system (or should be), and once the water has been added to the system, corrosion and mineral build-up are not significant, unless a lot of make-up water has to be added (because of a leak). The coils are most prone to clogging because the passages are smaller.

The issue of the pump noise is a little trickier. As mentioned above, it could be mounted directly to the concrete, instead of through rubber isolators. It could also be quieted by using pump isolators, as related in this story: http://www.hpac.com/member/archive/0009war.htm#noise . It could be cavitation in the pump (air coming out of suspension to form bubbles), which can also ruin the pump. It could be a bad bearing in the pump. It could also be that the pipe is rubbing against the floor & framing of the first unit.

If the pump wasn't underpowered when the system was designed and installed, I sincerely doubt it is now.

Original post -
Noisy pipes
Background: On demand hot water is pumped through twenty condo units. Also, each unit has a forced air hot water heating element. The outdoor pump is loud and wears out frequently. The noise and vibration travels up the pipe into the floor of the first unit. The pipes make a lot of noise in the unit.

Question: Is the pump under powered? Has eighteen years of mineral build up in the pipes and heating units caused a problem? What can be done to quiet the noise in the unit?
I won't want to drink that hot water, it was sitting in the coil for more than 3 months... if there was no problem 18 years ago then it is the problem with the maintenance... did they (management) ever look inside the piping,is there enough pressure/ flow at the top (farther) room... you building's hot water system will save money / problem with a variable frequency drive pump