Installation and venting problems with tank less heaters

If your household frequently takes back-to-back showers, you may be familiar with the "cold water sandwich. You turn on the shower and feel warm water at first, but then get blasted with several seconds of cold water before the temperature slowly climbs back up. When the second shower began, the initial warm water you felt was the trapped water.

Any cold water that you are experiencing in your shower is due to cold water living in the pipes between your water heater and your shower. The further your water has to travel from the water heater to its destination, the more noticeable the gap. Unfortunately, there's no way to prevent this, but now that you're aware of the problem, you can avoid jumping in the shower until the cold water has passed. For most tankless water heaters, the display with present an error code to inform you that your air supply or exhaust is blocked.

This means your water heater is having issues with either combustion air or venting. First, inspect all vent pipes to ensure they are connected properly and free from puncture holes. Refer to your product manual to make sure the clearance requirements are being met, as installing your water heater too close to other objects can block the air supply and create a fire hazard.

Birds nest, rodents and wasps nest can also block your venting, so be sure to thoroughly examine all vents that are located or lead outside your home. There are several reasons your water heater could fail to ignite. Often, this issue is caused by the gas supply, so check to make sure your propane tank is full before you do anything else.

If your gas valve or water valves are not fully opened, this could also cause the ignition to fail. Check and open gas and water valves fully. If these steps do not resolve the ignition problem, then either your ignition pack has failed or there's a bigger problem.

You should contact technical support to help you trouble shoot the issue and order replacement parts if necessary. Such types are often installed on the outside wall of the house and inside the recess box, protecting it from the cold weather and elements. You are even safe if you live in a region with below-freezing temperatures because tankless are often equipped with a system that automatically provides heating.

In contrast, condensing heaters can be vented with PVC and PP pipes, which are cheaper and easier to install and handle. Note : Every manufacturer specifies the maximum lengths that you can run the venting.

The number of elbows is limited because they shorten the total vent distance. If one tankless heater does not produce enough hot water for your home, you can combine more than two units into one system. As they can use a manifold to share the same vents, individual vent penetration is not needed, saving you time and money during installation.

Plus, it is more practical and aesthetically nicer to have fewer wall openings. Warning : Improper venting of any gas water heater can lead to carbon monoxide leaks and poisoning.

There are three the most used venting systems in residential water heating: atmospheric, direct-vent, and power-vent. They use flue ducts or a chimney to move the exhaust gases from the water heater to the outdoors.

Depending on the venting system, flue ducts can be metal or plastic. All rights reserved home-water-heater. Water Heaters Guide.

Tankless-indoor concentric. Tankless-indoor 2 pipe. Tankless-common venting. Tankless installation Venting tips Condensation Troubleshooting. Popular articles. Any condensate sloped towards the outdoors can cause ice formation problems. This lack of proper slope can be caused by not paying enough attention during installation, or from improper or broken pipe supports.

Either way a blockage can occur, resulting in another burner lockout and another service call. Soldering directly to fittings on a water heater is another error that can cause some serious problems. Damage to plastic components of the unit can result, especially to plastic dip tubes on many tank type heaters.

Instead of soldering directly to the unit, prep the fittings on the floor or a fireproof level surface. Allow fittings to cool before making the remaining solder connections further from the unit.

It can also help to wrap a cold wet rag around the copper pipe you are soldering to prevent heat from conducting to the unit. Premature activation of electric elements or gas burners prior to completely filling a tank is probably the final issue to avoid.

Whether done accidentally or because someone was in a rush to finish up, a dry fired tank can result in serious damage to electric elements or possibly cracking the glass lining of the tank. Make sure all the air is completely purged from the tank by opening a faucet and running the water until all the air is gone.

With government efficiency requirements climbing all the time for new water heaters, we can expect water heating appliances to continue to change and evolve. Taking the time to learn about the installation requirements for new equipment will always pay dividends for contractors by reducing installation problems and service calls. Attention to detail during the installation of a water heater will always result in more efficient operation, fewer nuisance callbacks, longer service life, and more satisfied customers.

He is a mechanical engineering technologist graduate of Humber College and has over 30 years experience in hydronic and solar water heating. He can be reached at solwatservices gmail. Exact matches only. Search in title. Search in content. Search in excerpt. View Digital Edition Digital Archives. How to solve water heater installation errors October 17, By Robert Waters.

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