7Maintenance
The Lochinvar SDT/SET series indirect water heater is an extremely simple device and as such requires very little maintenance. There are, however, several items which should be checked out on an annual or as needed basis to ensure a reliable supply of hot water:
*Make sure that the rest of the solar, boiler and domestic water piping is free of leaks.
*If there is an oil lubricated circulator in the system, make sure it is lubricated as called for by the circulator manufacturer.
*Make sure that the boiler is maintained in accordance with the boiler manufacturer’s instructions.
*If a water treatment system is required to keep the water chemistry within the parameters shown in Table 2A (see Section 2 -
Maintenance Schedule
Annual service by a qualified service technician should include the following:
Any procedure required by local codes.
Verify system pressure. Air venting procedure may require adding water to bring boiler system up to pressure, typically 12 psig.
Manually operate T&P relief valve at least once a year. This will release some hot water.
Before operating a T&P relief valve, make sure no one is in front of or around the T&P relief valve discharge piping. Hot discharge water can cause severe personal injury or substantial property damage.
Move operating lever to open position for a few seconds and then move it back, allowing it to snap closed. After the T&P relief valve is operated, if it continues to release water, close the cold water inlet to the water heater immediately. Follow the draining instructions, and replace the T&P relief valve. If the T&P relief valve weeps periodically, it may be due to thermal expansion. Do not plug the T&P relief valve or discharge piping.
Plugging the T&P relief valve or discharge piping can cause excessive pressure in the water heater, resulting in severe personal injury, death, or substantial property damage.
Follow instructions on circulator to oil, if required.
Check mixing valve, valves, pipes, and fittings for leaks.
Check function of the
Review homeowner’s maintenance responsibilities and their frequencies, including any not listed in the following section.
SDT/SET Installation & Operation Manual
Homeowner monthly maintenance to include:
Visually check valves, pipes, and fittings for leaks. Call a qualified service technician to repair leaks.
To Fill the Water Heater
1.Close the water heater drain valve by turning the knob clockwise.
2.Open the cold water supply shutoff valve.
3.Open several hot water faucets to allow air to escape from the system.
4.When a steady stream of water flows from the faucets, the water heater is filled. Close the faucets and check for water leaks at the water heater drain valve, combination temperature and pressure relief valve and the hot and cold water connections.
Water from opened drain valves, unions and other connections may be extremely hot. To avoid severe personal injury, death, or substantial property damage:
- Tighten all drain hose connections. - Direct hot water away from all
persons.
To Drain the Water Heater
Should it become necessary to completely drain the water heater, be sure to follow the steps below:
1.Disconnect the power supply to the heat source. Co n s u l t the plumbing professional or electric company in your area for service.
2.Close the cold water supply shutoff valve.
3.Open the drain valve on the water heater.
4.Open a hot water faucet to allow air to enter the system.
Drain the water heater if it will be shut off and exposed to freezing temperatures. Freezing water will expand and damage the water heater.
•If boiler water contains sufficient antifreeze, then only the domestic water needs to be drained.
•If boiler water does not contain sufficient antifreeze, the boiler water and the domestic water must be drained.
If antifreeze is used in the boiler water, check concentration. Boiler water (including additives) must be practically
Do not use automotive, ethylene glycol or
21 
