In this business, there are at least three ways to solve each hydronic control problem. The idea is, of course, to choose the approach that’s right for the application at hand, for you, and for your business.
One general recommendation is to choose controls that are reliable and simple to use. Look for products that are backed up with toll-free manufacturer support and clear technical and consumer literature.
Consider, too, sharpening your skills by enrolling in a good training program. The best training will bring you up-to-date on trends in oil and hydronic controls, and give plenty of hands-on problem-solving practice with actual residential oil and hydronic heating equipment.
Let’s begin by looking at some general problems and solutions, then move on to room temperature and noise problems.
Watch for this problem especially in older solar heating applications. The solar panels and tubing used may not have an oxygen barrier; although watertight, they are oxygen permeable. The oxygen corrodes the inside of the valve.
If you’re working with an open-air hydronic system or an oxygenated water application, look for valves designed for fresh water applications. (Honeywell’s VC valve is an example.)
Premature valve motor failure — The lubricant inside the motor can dry out under a combination of over-voltage, over-temperature, and high duty-cycle conditions, causing the valve motor to fail prematurely.
If the valve motor is constantly energized for more than a few hours per day, reduce the duty cycle of the valve. If the motor is energized for months during a system-off period, turn the valve off, too.
Insufficient hot water (in combination heating-hot water systems) — Combo systems are designed to both heat the house and supply hot water for showers, baths, and other domestic use.
If your customer complains of insufficient hot water, install a zoning panel with the domestic hot water priority feature. When there is demand for domestic hot water, the zoning panel turns off the home’s heating system and shunts all the energy into heating the water for the hot water tank.
Temperature swings in the spring and fall — Overheating in the spring and fall indicates an opportunity for outdoor temperature compensation, or OTC. Today’s OTC controls work by varying the hydronic loop supply temperature in proportion to the outdoor air temperature, and solve the problem of excess heating on mild weather days.
Thermostat location — Is the thermostat located correctly? Make sure it’s mounted on an inside wall. A thermostat mounted on an outside wall is a formula for discomfort. In cool weather, for example, it will be overcooled by the wall, needlessly calling for heat and resulting in too much warmth.
Thermostats should not be in the sun or where dead air will give a false reading. Here’s an exception: In separately zoned solariums or other sun spaces, the thermostat should be located in the sun.
Thermostatic radiator valves (TRVs) — TRVs can be used to rezone a room or space without having to repipe. Most contractors tend to use a centrally mounted or room-mounted thermostat versus one mounted on the radiator. Keep TRVs in mind as a potential solution where you have one thermostat controlling a large area or number of rooms.
Install TRVs to trim heat from overheated areas and get better balance without running room wires and installing extra thermostats.
Zoning — A zoning (or zoned temperature control) system helps maximize comfort in any type of home. Zoning can help eliminate problem areas that are too hot or too cold by delivering heating when and where it is needed.
Bedrooms, for example, may be kept at an energy-saving setting when vacant or used for sleeping, while the main living areas are kept warmer (or cooler) when they are in use.
Zoning also can compensate for dynamic load changes (i.e., solar gain on the south and west sides of a home).
Pumps and valves — With modern high-head pumps, noise can occur in larger installations with long pipe runs and multiple zones. Here are some ways to reduce noise:
Water hammer — Water hammer noise can be a nuisance. Here are pointers to consider:
You can encounter condominiums or larger commercial buildings where the zone valves near the pumping station have to deal with the greatest system pressure. Look for valves designed specifically to handle these punishing circumstances (i.e., capability to handle high close-off pressure, as well as providing a “soft close-off”). The Honeywell VC valve is one example.
Air in system — Make sure you’ve got proper air removal with an air separator in the common supply piping and with air vents on the boiler and radiators.
Pumping away or pumping into the boiler? Pumping away is the best, but most important is that you locate the expansion tank near the intake side of the pump.
It is preferred to have the expansion tank on the high-temperature supply side of the boiler. This arrangement increases the pressure in nearly all parts of the system when the circulator operates, and prevents problems with air in the system.
Locate the air separator on the supply side too, because that’s where most of the air is generated. It comes out of the water at its highest temperature.
When you’re familiar with the range of solutions, you can select the approach that’s best for the application and your business.
To learn more about troubleshooting, take advantage of a good hydronic control training program that emphasizes hands-on learning.