High Efficiency Water Heaters

Servicing High Efficiency Water Heaters

Is it time to service your high efficiency water heater?

New efficiency standards for water heaters have been set by the Department of Energy and these standards went into effect as of April 16, 2015. The good news for consumers is that these new standards will save energy. The bad news is that some high-efficiency equipment, notably gas water heaters and boilers, are not like your mom and dad’s water heaters; they are complex appliances with circuit boards and complex heat exchangers and they require regular servicing if they are going to work reliably and efficiently.

Is your water heater a new, high efficiency model?

The first thing you want to know is if your water heater is a high efficiency appliance or not and it’s pretty easy to figure this out:

  • If you have a tankless water heater or any type of boiler system or water heater that vents out the wall of your house or with PVC piping for flue material, then you likely are the proud owner of a high efficiency water heater or boiler.
  • Less efficient equipment will either run off electricity, or have a metal flue pipe that needs to vent into a chimney our out through your roof.

Why should I service my water heater? My mom and dad never did!

When it comes to the useful service life of heating equipment, there is one important guiding principal to understand: as a general rule, we trade service life for efficiency. This means, the less efficient the heating equipment is, the longer it is likely to last.
On home inspections, I often receive protests from clients when I inform them that their newer high efficiency furnace has a design life of only 15-20 years.
“What do you mean,” they say, “I grew up in a house with a furnace that was over 50 years old.”
This is true. But that old furnace has a thick metal heat exchanger that is difficult to heat and very hard to wear through. Visualize the heat exchanger as a thick metal clam shell that contains the products of combustion and vents them out the flue. When that metal heats up, you pass air or water across the outside to heat it up. By the time you heat that thick metal up hot enough to heat your home, you have lost lots of the energy out the flue. As a result, these older furnaces and boilers tend to be 60-80% efficient compared to newer gas equipment that is 90-95% efficient.
According to John McGinn, at Swift Plumbing in Seattle, the old water heating equipment – 80% efficient and less – was so simple it did not even require annual scheduled maintenance. In addition, this older less efficient equipment is not so expensive to replace, so it made less financial sense to perform regular scheduled maintenance. Not true of these new high-efficiency water heaters; these are expensive pieces of equipment that can cost as much to replace as your furnace.

  • Dylan Chalk photo of clogged filter in hightect waterheaterIf you don’t do annual servicing and cleaning, the heat exchangers on the inside will clog up with scaling and mineral build-up causing the heaters to work less reliably and less efficiently and even fail completely.

The photos attached show sediment build-up in relatively new water heaters.

Maintenance needed

Many conscientious home owners are accustomed to servicing their furnaces but not their water heaters. If you have a high-efficiency water heater or boiler, protect your investment and do scheduled annual maintenance to keep the appliance working safely and efficiently.


Dylan Chalk is a home inspector and the owner of Seattle-based Orca Inspection Services LLC – www.orcainspect.com. He is also the founder of ScribeWare software offering innovative and simple report writing solutions. Follow his house-hunting tips from the field on Twitter @ https://twitter.com/dylanchalk1. Or see his blog @ http://getscribeware.com/blog

Dylan Chalk

Dylan Chalk is the owner of Seattle-based Orca Inspection Services LLC – www.orcainspect.com. He is the founder of ScribeWare inspection report software offering innovative and simple report-writing solutions – www.getscribeware.com. He is also the author of The Confident House Hunter – a book to teach home buyers how to look at and understand houses: Cedar Fort Press Due out July 2016 – www.dylanchalk.com

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