Northern Heatpump NorthStar RD-WE-096 Installation & Operating Instructions Manual - page 31
08/19/2014
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NI701
Preventive Maintenance
Source Coil Maintenance –In closed loop systems, water coil maintenance is generally not needed. However,
if a dirty installation or deterioration of the piping has caused debris to accumulate in the system, the water coil
should be cleaned using standard cleaning procedures. For open loop systems installed in areas with a high
mineral content, it is best to schedule regular periodic maintenance to inspect and clean the coil if necessary.
Should cleaning become necessary, do so using the following standard cleaning procedure:
- Chlorine Cleaning (Bacterial Growth)
1.
Turn thermostat to “Off” position.
2.
Connect a circulating pump to hose bibs on entering water and leaving waterside of heat exchanger.
3.
Using a five-gallon pail of water add chlorine bleach mixture. The chlorine should be strong enough to
kill the bacteria. Suggested initial mixture is 1 part chlorine bleach to 4 parts water.
4.
Close shut off valves upstream and downstream of heat exchanger.
5.
Open hose bibs to allow circulation of bleach solution.
6.
Start pump and circulate solution through heat exchanger for 15 minutes to one hour. Solution should
change color to indicate the chlorine is killing the bacteria and removing it from the heat exchanger.
7.
Flush used solution down the drain by adding fresh water supply. Flush until leaving water is clear.
8.
Repeat procedure until solution runs clear through the chlorine circulation process.
9.
Flush entire heat pump system with water. This procedure can be repeated annually, semiannually, or as
often as it takes to keep bacteria out of the heat exchanger, or when bacteria appears in a visual flow
meter to the point the flow cannot be read.
- Muriatic Acid Cleaning (Difficult Scaling and Particle Buildup Problems)
Consult installer due to dangerous nature of acids.
Iron out solutions and de-scaling products are also useful
Fan Coil Air Filter Maintenance – A dirty fan coil air filter will result in lower efficiency and performance.
Under normal operating conditions, a monthly cleaning or replacement should be satisfactory.
Heat Pump Water Coil Maintenance – (source or loop) In closed loop systems, water coil maintenance is
generally not needed. However, if a dirty installation or deterioration of the piping has caused debris to
accumulate in the system, the water coil should be cleaned using standard cleaning procedures. For open loop
systems installed in areas with a high mineral content, it is best to schedule regular periodic maintenance to
inspect and clean the coil if necessary. A dirty or fouled heat exchanger can cause the units to trip either low or
high pressure. Should cleaning become necessary, do so using the following standard cleaning procedure: see
water coil preventive maintenance.
Fan Coil Condensate Drip Pan and Drain – Inspection and cleaning of the condensate drain system during
the cooling season will help prevent the system from plugging up, potentially causing water damage to your
structure and floor coverings. Inspect the condensate drain line to make certain it remains clear of obstructions.
In some areas, airborne bacteria can cause algae to grow in the drip pan. In these areas, it may be necessary to
treat the drain pan with an algae inhibiting chemical, as this algae together with lint and dust could plug the
drain piping. Fan coils with the water coil in a negative pressure chamber will need a trap that is vented after
the trap for the condensate to drain properly.
Water/Air Coil – In order to keep your fan coil operation at peak efficiency, the air coil should be inspected
and cleaned when necessary. If the coil is excessively dirty, the coil can be cleaned with a household vacuum
cleaner and a soft brush. The aluminum fins are fragile and bend easily, so take great care not to damage the
fins, and remember these fins are sharp, so take the needed safety precautions.