Category Archives: Low Temperature District Energy Sharing Systems

Buffer Tank Pump

Heating systems used in the Cheakamus Crossing development use radiant floor heating and fan coils. Water heated in the buffer tank is circulated by a three speed Grunfos pump. When the heating system first starts in the fall it is important to check for proper circulation. The circulation pump has not run for several months and there is a chance that air has built up and can prevent the pump from circulating water and cause the pump to fail.

Image of pump and PEX piping
Buffer Pump and PEX Piping

Turn up a few of the thermostats so several zones will call for heat. Within 5 minutes the pump should start. There may be some gurgling at the start but should stop after a few minutes.   The gurgling sound is from air in the system which is common in many of these units and difficult to completely eliminate.   There are automatic air bleeders installed on the heating system and an air scrubber of the heat pump circulation but do not always work. Some air bleeders are poorly placed or can fail if the vent plugs up.

Air trapped in the system will compress and prevent the water circulation. Without water moving through the pump it will over heat. There are several reasons why the pump can fail but air trapped in the pump has been an issue and happens most often at the beginning of the season or after the pump has been off for an extended period.

It is not obvious on these systems that water is circulating, it may sound like the pump is running but there may be little or no water circulating. You will need to remove the access panel on the first floor to see the radiant floors valve headers. Flow indicators on the top or bottom of the valve header should move on the zone valves that are open. If the actuator is raised and the pump is running, there should be movement on the flow indicator. If the actuator is down then the flow should be zero.

In floor heating
In floor heating

If there is no flow through the pump, the body of the pump will get very hot, too hot to hold your hand on it without burning. These pumps are fairly tough and can handle a little overheating, but if it is left to overheat for several hours will cook the bearings and the pump will have to be replaced.

If there is problem, then call a service technician to look at the system. They may be able to save the pump and correct the problem. There will be a reason for this problem, do not just replace the pump without identifying the issue. These pumps should last ten years or more. If the pump fails and issue is not corrected it will fail again. Some unit have already had this circulation pump replaced 3 times.

Call Western Technical System 604-849-0463

Cheakamus DES Heat Pumps

There have been four compressor failures this year, that we are aware of, in the Cheakamus Development in Whistler, BC. At least two, and possibly the others as well, could have been prevented. If you have a Red Screen on your system, there is an issue with your heat pump that needs to be corrected. You can try to reset it once, but that’s it. Leave the Red Screen on and the system will use the electric back-up heat. Think of it as a car when the oil light comes on.

Scaling has become an issue, Well water is safe to drink, but it is full of minerals. These minerals result in scale inside the heat exchanger and will cause the unit to run hotter and over pressurize. If you continue to reset the unit, the compressor will burn out, then you will have to replace the compressor and clean the heat exchanger. This is a difficult process on these units, as they are hard to access. It also took sometime to find an effective chemical that did not damage the system, and still cleaned the heat exchanger. We do not know how often it will be required to be cleaned, however, I suspect once every few years. There are ways to improve the water quality, but it will always be an issue.

CC-heatpump

Gas boilers have the same problem in Whistler. Another issue is that the original capacitor, on the original Climate Master Heat Pumps, have been failing regularly. When the capacitor fails, it will cause the compressor to overheat and can result in compressor failure. The unit will not Red Screen (remember, like the oil light coming on in the car, to alert you for service) and will keep trying to run until the compressor gets smoking hot. If the original capacitor is still in place, it should be replaced ASAP. When you do call a service company, you need a Licensed Journeyman Refrigeration Technician to diagnosis the Heat Pump. If the company cannot send a Refrigeration Technician, call someone else. If you have a water leak, call the plumber, but an issue with the heat pump, requires specialized skills.

There have been a few issues with heat pumps, and several residents have spent thousands of dollars, only to have the systems misdiagnosed and still left with having to spend more money to have it fixed properly. I will not discuss the technical details of the issue, as this will result in unskilled people trying to resolve the problems. With heating systems this complicated, a little bit of knowledge is a dangerous thing. Here are a few simple things to look for:

-If the heat pump display is flashing “Heating” or “Hot Water” the compressor should be running within a few minutes. If you cannot hear the hum of the compressor, turn your heat pump off and use the back up heating.

-The two red water pumps, above the heat pump are used for circulating hot water for the potable hot water tank and the in-floor heating system. This pump should be warm when running but not hot. If you cannot comfortably hold your hand on the body of the pump, then it’s too hot. Turn the breaker off to the heating controls and call for service. The pumps are fairly tough and can handle a little over heating for a short while, but left unchecked it will burn up the bearing.
If you have items stored next to the heat pump, use precautions to prevent damage to wiring and piping. There have been a few cases, where a ski or boots have knocked a valve open or closed and shut down the system.

– Check the drain pans under the water storage tanks, these should be dry. Water in the pan indicates a leak that needs to be fixed. If the system leaks water, it will be continuously replenished from the feed regulator and operate normally. However, it will deteriorate the water quality of the heating loop and affect performance. This system was designed to have a low Green House Gas (GHG) foot print, and still have reasonable heating cost.

If you want cheap, use a High Efficiency Natural Gas. It is definitely the cheapest heating system available, but then there is that small issue of Climate Change and life on this planet, ending as we know it. The monthly operating costs on this system is low, however, you can expect to spend any savings on maintenance. Properly maintained, the maintenance cost will be reasonable, poorly maintained systems will not be. If you think the operating cost is high, just turn your heat pump to the off mode and let the electric heaters take over. You can check your daily consumption online at bchydro.ca, however, you do not want to wait the two month period for the bill to come in, unless you have money to burn.

For service on the system call Western Technical Systems at 604-849-0463