November, 2009
Inspection News and Views from the American Society of Home Inspectors

How a Plumber Inspects Plumbing: Toilets


The flushes of the future – dual, pressured or powered

Whether I’m wearing my plumber or my home inspector hat, my clients want to know what’s new in water conservation  and how their fixtures and systems stack up. A simple chart helps me explain how much water can be saved with specific toilets. But I know I’ll need to explain much more as new systems and fixtures are introduced. Have you seen a residential toilet without a tank? They are on the market.

The push for reducing the water used to flush a toilet begins with low-flow fixtures. Under U.S. federal law, toilets sold today must use 1.6 gallons of water or less per flush. They are generally classified as low-flow toilets. High-efficiency toilets (HETs) are a step up from low-flow ones. HETs use 20 percent less or 1.28 gallons per flush (GPF). Some toilet makers are topping this number. Low-flow, high-efficiency and dual-flush toilets have changed toilets dramatically over the past decade or so. If you aren’t already finding these new models in the homes you inspect, you’re sure to see them soon. To enable toilets to effectively remove waste with a mere gallon and a half of water, flush valves have gotten larger; trap-ways are often bigger and even the china quality in toilet traps has improved. But many basic low-flow toilet components work much like their older forerunners. Because of the use of popular fill valves like the Fluidmaster 400A in the low flow-toilets, do-it-yourselfers can still make basic repairs. When used, flapper-type flush valves are similar to the 2" devices used in the past, but many have evolved into a 3" size. This allows a quicker dump of water from the tank to the bowl.

Dual-flush toilets

Dual-flush toilets allow the user to send half the water down the drain when solid wastes are not an issue, and the full amount of water when it is needed. To do this, on some toilets two buttons replace the trip-lever-style flush mechanism and a two-level flush valve is used. Other models kept the lever, but you lift it for the reduced water flush and push it for the full amount. Dual-flush retrofit flush valves have been available for years. Twenty-five years ago, I installed them on 3.5 GPF toilets to reduce the amount of water sent to waterlogged septic fields. Today, they are more likely to be installed for families going “Green.”

AquaPro Solutions, llc, a maker of dual-flush toilets, also sells a dual-flush converter for 1.6 GPF toilets. Sold as the Dual-Flush Pro Conversion kit, it includes both fill and flush valves, which allows for critical adjustments so the installer can get the right flush for both solid and liquid flushing, using the minimum amount of water necessary to do the job. The trip lever with this device is designed to be moved in one direction for the lowest volume flush and the opposite direction for a regular flush.

Another dual-flush converter from Aquanotion Ltd. is sold as the TwoFlush and will work on older 3.5 and 1.6 GPF toilets. Both the Aquanotion and AquaPro Solution devices are reasonably priced, so they’re likely to turn up during an inspection. Be sure to flush the toilet in both modes during an inspection and include a handful of paper for the solid flush. I also recommend demonstrating the flush actions to your client.

Illustration: With the growing interest in water conservation, be prepared to answer clients when asked how to compare the use of water by the variety of toilets now readily available.
Illustration courtesy of Caroma

Dual-Flush Toilet Components

Photo: Looking from above, you can clearly see two flush levers attached to the flush valve with the TwoFlush retrofit dual-flush device. Photo by Joe Mulho, Aquanotion, LTD


Photo: The AquaPro Dual-Flush Pro Conversion kit.

Photo by Chris Hanson, AquaPro Solution, LLC


Pressure-assisted flushing

Probably, Sloan builds a unique system for efficient flushing. Called the Flushmate®, it falls under the category of a pressure-assisted toilet. These systems are being installed in several major brand toilets and are not a retrofit for a standard gravity-fed toilet. According to Paul Deboo of Flushmate, the system gets the energy necessary to make the powerful flush from the supply water pressure. As the water enters the tank, it collects in a closed compartment along with the air compressed during the fill. When flushed, the pressure, which can be as much as three times normal flush pressure, blasts through the bowl, forcing the waste through the toilet trap-way. Standard gravity toilets usually suck the waste through.

Photo: Pressure assisted Flushmate. 
Photo by Kenny Hart

Illustration: Pressure assisted Flushmate.  
Illustration courtesy of Flushmate

Paul informed me that the Ultra Low Flush (1.6 GPF) model requires at least 20 psi and 25 psi for the High-Efficiency Toilet (1.0 GPF) model to operate properly. If you come across these systems during an inspection, you might want to point this out to your clients. This is especially true if they have water pressure issues. Paul also noted that the sound of the Flushmate system is their performance signature. The flush occurs quickly, so the sound duration of the flush is very brief.

My experience with these systems is somewhat limited, but I repaired leaks on two toilets that employed the Flushmate system. In both cases, my customers complained of finding water on the floor behind the bowl. And in both cases, they only leaked when flushed, and the source of the leak was the tank-to-bowl gasket. As the water blasted from the tank, it sprayed from the tank-to-bowl connection. The installer had failed to tighten the tank bolts properly. I quickly corrected the problem with an opened-end wrench. But perhaps because of this problem, I look at this connection closely when inspecting these toilets.

Power-assisted flushing

Power-assisted toilets are now showing up in some high-end homes. Some of these toilets, such as the tankless Kohler Purist® Hatbox®, use a small pump to move water and waste from the bowl. Some of the power-assisted toilets qualify as HET toilets. Power-assisted toilets are new to the scene, and with a list price of over $4,000, it’s unlikely you’ll be inspecting them every day. Unlike the traditional toilet, a 120-volt outlet with GFCI protection is required for proper oper-ation of a power-assisted model.


Photo: Kohler Purist® Hatbox® toilet.

Photo courtesy of Kohler

Recycling flushes

The trend to use smaller amounts of water to make the flush has some toilet makers producing toilets that allow the water used for the flush to be used twice. Now, before you cringe with disgust, it’s not what you think. Safely recycling used toilet water, or black water, is quite doable, although not cost-effective for a single-family residence. Using the water on its way to a flush, however, is affordable and being done now. In areas where reduced water consumption is a high priority, you will likely see a toilet like the Caroma Profile Smart, a dual-flush toilet that incorporates a sink in its lid.


Photo: A recycling flush toilet from Caroma.

Photo courtesy of Caroma

Typically, when a toilet is flushed, the tank is refilled through the fill valve and water flows directly into the tank for the next flush. With the Profile Smart, the water is diverted through the faucet in the tank lid. The idea is to provide water for hand washing once the toilet is flushed. After the water flows over the users hands, it pours into a drain opening in the lid and then into the tank.

On the next flush, it becomes part of the water that clears the bowl.

Is there more to learn about toilets?

In the final installment of this series, I’ll share my experiences dealing with what is the plumbing defect I report more than any other — toilets loose at the floor. I’ll point out the common causes, potential damages and I’ll offer up some quick and long-term fixes for this problem that can be passed on to clients.


Getting it Right: Joining Two-Piece Toilets

Most of the toilets I find on my inspections are two-piece, joined by either two or three bolts with tank-to-bowl gaskets. The three-bolt models tend to be more stable, while the two-bolt units often allow the tank to move in a back-and-forth motion, resulting in a broken tank or supply tube. Usually, this problem can be traced to oversized, soft gaskets, which are difficult to fully compress, sandwiched between the tank and bowl. When I observe a tank that moves or rocks in this way, I write it up as an unstable tank. To make the repairs, a different style gasket and sometimes rubber spacers or cushions are needed between the tank and bowl.

In both two- and three-bolt models, leaks can develop at the tank bolts and tank-to-bowl gaskets. Leaks at the bolts tend to be constant or to occur when someone presses on the tank by resting against it. Tank-to-bowl gaskets leak primarily when the toilet is flushed. Both leaks are often evidenced by a blue stain down the backside of the bowl or behind the bowl on the floor. As a home inspector, I look closely for these stains or for moisture if blue bowl cleaners are not in use.

Photo: The tank bolt on the right, shown with the metal under the bolt’s head, will be more prone to failure if installed this way. The left bolt, shown with the washer directly under the bolt’s head, is correct.
Photo by Kenny Hart

As a plumber, I rock the bowl slightly when checking for leaks, but I don’t recommend this for home inspectors. Inspectors should look closely for evidence of past leaks and note the tank’s proximity to the wall. My experience as a plumber has shown me that a tank that sits well away from the wall is more likely to leak than one that rests comfortably against it. This is especially true with two-bolt tanks. The wall seems to provide some support that prevents backward movement.

Do-it-yourselfers often install bolts improperly. In their defense, I have seen imported bolts with poorly illustrated instructions. The large head of the bolt should compress a rubber washer against the china surface of the inside of the tank. Many do-it yourselfers pass the bolt through a metal washer before sliding it through the rubber washer. Not only is this unnecessary, it creates a metal-to-metal surface contact and will often end up quickly corroding. Observers looking down on the bolts through the tank water will sometimes see an almost mushroom-like growth over the head of the bolt within a few months after installation. Inspectors who see this should look closely at the underside of the bolts for dampness or an active leak, but should never probe them.

The large head of a quality tank bolt pressing against the top of the rubber washer and pulling it directly against the tank’s china surface does the best job of sealing the bolt hole.



Doing it Right: Is This the Right Toilet?

ASHI regularly publishes Postcards from the Field depicting defects so obvious that they are amusing. Most defects are less obvious and the outcomes anything but funny. For instance, the standard installation of drain piping and toilet flanges puts the center of the flange roughly 12” from the wall. However, structural constraints such as joints or beams might require it to be placed a bit closer or farther away. To accommodate variations, toilets designed for a 10” and 14” placement are also available. If a standard 12” model toilet has been set on a 14” installed flange, the toilet tank will rest about 2” from the wall instead of just slightly ahead of or against it. It is unlikely that an installer could get a 12” toilet to mount to a flange installed for a 10” toilet, though they might try. If this was done, it would sit so far forward on the flange it would leak when flushed and routinely stop up.

When I see toilets that look as if they will be replaced, or hear my client speaking of replacing the fixtures for the bath, I alert them to this subtle variation and recommend they do the following: Measure from the wall to the center of the closet/toilet bolts that hold the bowl to the floor, then take this measurement to a toilet supplier and have a professional match the number with the correct toilet. The measurement for a standard toilet should fall between 11 1⁄4” to 13”. Depending on tank positioning and the brand, sometimes you can squeak by with numbers that are slightly higher or lower. Measurements well short or beyond these numbers could cause the bowl to set forward of the flange’s center, making it prone to stoppage, or set too far from the wall, making two-bolt tanks prone to rocking.

Photo: When replacing a toilet, a measurement should be taken from the wall to the center of the closet/toilet bolts that hold the bowl to the floor.   Photo by Kenny Hart