Water Heaters - Instantaneous Water Heaters
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gianni
03-19-06, 06:31 AM
Hello All;
back in September 05 I installed a Bosch Aquastar 250 SX water heater after a long time researching and reading. Here are some of the lessons I've learned. Any feedback on these would be greatly appreciated;
1. Check to see what the required static gas pressure needs to be for the instant hot water heater you plan on buying. Then check to see what your gas company will provide. I found that my unit requires a minimum of 6" WC when my gas company only gaurantees 3" WC. My gas company was able to increase the pressure in my lines to just around 6" WC, but I still have some minor issues where my unit is gasping for gas.
2. Try to install 2 handle faucet controls. While you ideally want to set your water heater temperature to 1 constant temperature, it is not really that practical. Make your life easier, install 2 handle units and set your tankless heater to 120 degress. While this does reduce the efficiency a bit, it keeps the wife happier and that makes for an easier life all around.
3. There is a delay for these units to fire up and begin cranking out hot water. That delay will be made worse if you are using one of these units to heat an entire house. My unit is not centrally located. Combined with a 3200 sq ft home...well, i should have considered better unit placement or considered 2 units.
4. Get an installer who has experience with these units. My installer had never done one before. While he did an ok job, he was the one who pushed for the current location of the unit. Had a more experienced installer been involved, he would have realized that there are more venting options an that we had more choices for unit location.
5. Lastly, make sure your wife understands the difference between a tank water heater and tankless. My wife just knows that she can't get hot water how she wants it and that makes her hate the water heater :)
As I said before, any feedback greatly appreciated. Also, any ideas if having higher gas pressure in my lines is bad for anything else?
Thanks!
back in September 05 I installed a Bosch Aquastar 250 SX water heater after a long time researching and reading. Here are some of the lessons I've learned. Any feedback on these would be greatly appreciated;
1. Check to see what the required static gas pressure needs to be for the instant hot water heater you plan on buying. Then check to see what your gas company will provide. I found that my unit requires a minimum of 6" WC when my gas company only gaurantees 3" WC. My gas company was able to increase the pressure in my lines to just around 6" WC, but I still have some minor issues where my unit is gasping for gas.
2. Try to install 2 handle faucet controls. While you ideally want to set your water heater temperature to 1 constant temperature, it is not really that practical. Make your life easier, install 2 handle units and set your tankless heater to 120 degress. While this does reduce the efficiency a bit, it keeps the wife happier and that makes for an easier life all around.
3. There is a delay for these units to fire up and begin cranking out hot water. That delay will be made worse if you are using one of these units to heat an entire house. My unit is not centrally located. Combined with a 3200 sq ft home...well, i should have considered better unit placement or considered 2 units.
4. Get an installer who has experience with these units. My installer had never done one before. While he did an ok job, he was the one who pushed for the current location of the unit. Had a more experienced installer been involved, he would have realized that there are more venting options an that we had more choices for unit location.
5. Lastly, make sure your wife understands the difference between a tank water heater and tankless. My wife just knows that she can't get hot water how she wants it and that makes her hate the water heater :)
As I said before, any feedback greatly appreciated. Also, any ideas if having higher gas pressure in my lines is bad for anything else?
Thanks!
majakdragon
03-19-06, 06:49 AM
I will only add that I hope you can find a plumber who knows how to work on repair items for this unit should you need it. Many plumbers do not install these units because they are not familiar with them. Those that do, usually charge more and sometimes parts are not readily available. Good luck.
Sharp Advice
03-19-06, 12:24 PM
Hello: gianni.
Excellent dissertation and observations. Others members should know or need to know before considering purchasing any instantaneous water heater.
More on the topic here:
TANK LESS WATER HEATER HELP LINK:
Tank less Water Heater Help & Informational Link:
http://forum.doityourself.com/showthread.php?threadid=147262
I usually do not quote any parts or aspects of a question unless I can determine it is necessary to do so. In this case I did so because of the nature of the question:
Also, any ideas if having higher gas pressure in my lines is bad for anything else?
There is rarely any need to increase gas supply line pressure. Only in very large complexes is higher than normal pressure used. Normal natural gas pressure in the main supply line for a residential house is between 7.5 to 10 inches water column pressure. Which is about 1/3 of a pound or so.
Each individual appliance than steps that down to 3.5 to 4 inches water column pressure. So increasing the supply pressure does nothing benefical and may do more harm than good. Gas volume is essential, not pressure so much. To have proper gas volume delivery, there has to be proper pipe sizes for natural gas, as well as propane. Too little volume effects proper appliance operations, not just pressure alone.
Any doubts about gas pressures, whether natural or propane, contact the supplier. The equipment to set the correct delivery pressure and volume out of the meter for natural gas is the responsibility of the supplier and not that of the customers. Nor should any customer and/or plumber etc. make any adjustments to any natural gas equipment, period.
Web Site Host, Gas Appliances Topic Moderator & Multiple Forums Moderator. Energy Conservation Consultant & Natural Gas Appliance Diagnostics Technician.
Personal Driving Safety Reminder:
Buckle Up & Drive Safely. "The Life You Save, May Be Your Own."
Excellent dissertation and observations. Others members should know or need to know before considering purchasing any instantaneous water heater.
More on the topic here:
TANK LESS WATER HEATER HELP LINK:
Tank less Water Heater Help & Informational Link:
http://forum.doityourself.com/showthread.php?threadid=147262
I usually do not quote any parts or aspects of a question unless I can determine it is necessary to do so. In this case I did so because of the nature of the question:
Also, any ideas if having higher gas pressure in my lines is bad for anything else?
There is rarely any need to increase gas supply line pressure. Only in very large complexes is higher than normal pressure used. Normal natural gas pressure in the main supply line for a residential house is between 7.5 to 10 inches water column pressure. Which is about 1/3 of a pound or so.
Each individual appliance than steps that down to 3.5 to 4 inches water column pressure. So increasing the supply pressure does nothing benefical and may do more harm than good. Gas volume is essential, not pressure so much. To have proper gas volume delivery, there has to be proper pipe sizes for natural gas, as well as propane. Too little volume effects proper appliance operations, not just pressure alone.
Any doubts about gas pressures, whether natural or propane, contact the supplier. The equipment to set the correct delivery pressure and volume out of the meter for natural gas is the responsibility of the supplier and not that of the customers. Nor should any customer and/or plumber etc. make any adjustments to any natural gas equipment, period.
Web Site Host, Gas Appliances Topic Moderator & Multiple Forums Moderator. Energy Conservation Consultant & Natural Gas Appliance Diagnostics Technician.
Personal Driving Safety Reminder:
Buckle Up & Drive Safely. "The Life You Save, May Be Your Own."