DIP TUBE FAILURES - EXTRACTED FROM THE WEEKLY HOME INSPECTION INDUSTRY ONLINE NEWSLETTER THE MONDAY MORNING MESSENGER
This weeks Technical Tip deal with a topic that I had never before given much thought to. It was originally spurned by my sister-in-law who was struggling with her landlord to get more hot water in their unit. When she inquired with me as to what the reason for short hot water supply I gave her all of the standard answers.....
- Have you checked the thermostat?
- When was the tank drained last?
- When was the unit installed? and by whom?
- Could the cold supply water be installed on the hot water side?
None of these questions resulted in an answer. The landlord had been out to the property within the last week, drained the unit and flushed the sediment. None of this made any difference. It was then that I received some information from another inspector. More internet searching yielded a new condition/solution to me. The following is the article that I authored for my newspaper column, as well as the resource info that I used to compose my piece.
Dip tube failures can cause cold showers
The all too familiar story was recounted, "I take my normal shower and there is only about 4 minutes of hot water. What is wrong with my hot water heater?" This can be very frustrating for consumers who don't understand how typical hot water heating systems work. Although this could be extreme sediment build-up in the water heater tank, improper installation, or a turned down thermostat, new information shows that it could very well be a failed dip tube inside the hot water heater.
Perfection Corporation is the manufacturer of 90% of the dip tubes used in domestic manufactured water heater units. This includes most of the popular brands used in Utah such as: Bradford-White, A.O. Smith, and Rheem. Perfection Corp. says that a small percentage of their plastic dip tubes produced between 1993 and 1996 have been found to fail. When the dip tube fails, the amount of usable hot water is significantly reduced.
A dip tube is a pipe which brings cold water into the water heater. Cold water enters the top of the heater and runs down through the dip tube to the lower portion of the tank. The cold water is discharged low in the tank so that the electric heating element or gas flame can more efficiently heat the cold water. This allows the entire upper portion of the tank to hold only hot water.
When the dip tube breaks off up higher in the tank it improperly allows the cold water to discharge into the top portion of the tank rapidly cooling off the hot water. This creates a very short supply of hot water, thus a very short hot showering time.
The Perfection Corp. was made aware of this condition back in 1996 and they remedied the condition in the dip tube manufacturing process. Much to their credit they also notified the Consumer Product Safety Commission when they realized what was happening but the CPSC did not issue a recall. Russ Rader of the CPSC said in a Supply House Times article, "We looked into the dip tube issue a while ago and did not find a safety hazard that would warrant further investigation."
Perfection Corp. reports that there have been 11,555 returns on the 24 million water heaters that could be involved. That is a very low percentage of failed dip tubes. It appears that the only people who are really concerned with the situation are those that can't take long hot showers or baths.
The water heater manufacturers are very helpful to those experiencing low amounts of hot water. The units in question are still under warranty and so needed repairs are made without financial burden to the consumer or the repairmen. Ultimately the Perfection Corp. is the one paying the final bills.
I called a large professional plumbing supplier, BJ Plumbing in Orem, to inquire with them if there were any consumer complaints being made to them. BJ Plumbing carries Bradford White water heaters and deal mainly with professional installers. They have not had a single complaint or report, but they said that the repair is a pretty simple one. Once identified as the cause, the dip tube is easily replaced within the existing unit. Rarely is it necessary to replace the entire water heating unit for a low hot water supply symptom.
Along with the dip tube replacement, it is very important that the tank be drained, the home's interior supply lines flushed, and the faucet aerators cleaned. When the dip tube fails it allows the plastic particles to spread throughout the supply system. Along with the lack of hot water is the low volume symptom at the faucets. A key indicator of dip tube failure is to remove the faucet aerators and look for small plastic particles clogging the screen.
To identify if your water heater is part of the group that could be affected, try to figure out how old the unit is. If you have been in the home since 1993 and have never upgraded it, then it is older and not in the targeted drip tube failure category. However, since water heaters generally carry a 5 or 6 year warranty you should be preparing for the inevitable upgrade of the entire unit. The typical lifespan of water heaters is 8 to 12 years, but I have seen some last 2 years and others over 25.
The manufacturing date of the unit is usually concealed within the serial number found on the label on the outer case of the water heater. The manufactured year is usually identified in the first 4 digits of the serial number.
It is sometimes difficult for the most seasoned inspector to make out the date from the info on the label, so other clues are sometimes relied upon. For example, if the unit is avocado green in color you are looking at a unit that has far exceeded its projected lifespan and was likely manufactured in the 1970's. If your unit is avocado green, forget about upgrading the dip tube and strongly consider upgrading the water heater unit before it fails.
When a water heater fails it can be a messy experience. Sometimes they just quit heating. That is an easy diagnosis and a straightforward upgrade for a plumber. This condition is usually realized first thing in the morning as the shower is drawn for the home's breadwinner while preparing to leave for work. Although irritating, no major physical damage is done.
The more common water heater failure involves a tank failure. This means a potentially messy situation. Some Utah homes are well designed so that a ruptured water heater flood runs directly towards and into the basement drain. Many homes have drains, but because of poor design the water soaks into surrounding carpeting on the roundabout way to the drain. This increase the damage because the unit needs to be replaced, walls can wick up moisture, and the carpet and padding needs to be taken up and dried.
The worst situation occurs when the tank ruptures and there is no floor drain. This turns the basement into a swimming pool, but at least it is heated. Homeowners are well advised to budget and plan for water heater upgrades before the tanks rupture. So if your dip tube has failed you should console yourself with the fact that your water heater challenges could be a lot worse. Dip tubes are easily and pretty inexpensively replaced.
(Michael Leavitt is certified by the American Institute of Inspectors. He is the owner of Michael Leavitt & Co Home Inspections and serves Utah County and beyond. Column suggestions or inspection questions are welcomed by visiting his website at www.TheHomeInspector.com, or by calling his office at 225-8020.)
