How To Convert Low Flow Toilet to High Flow: Here’s a Fix

If your toilet isn’t flushing properly, changing the flow can be a fix. Unfortunately, most modern toilets are “low flow”. What can you do about it? 

While there’s no changing the flow of a toilet, you can take steps to improve how your toilet flushes. We’ll go over those, as well as what could be causing flushing issues in your toilet. Then, we’ll cover some ways you can try to convert a low flow toilet to a high flow. 

Can You Convert Low Flow Toilet to High Flow?

The short answer is no. Flow rate depends on the size of the tank, the size of the jet holes, and the size of the mechanism between the toilet tank and the bowl. A traditional or old-school toilet bowl holds anywhere from 8-12 gallons of water. A modern “low flow” toilet can hold anywhere from 1.2-1.6 gallons. The difference in tank size is significant. You’ll never get the same flushing power out of a low flow toilet. Most importantly, you’ll never get your low flow toilet to meet the tank capacity of a high flow toilet. 

For example, even if you were to swap out the tank on your low flow toilet for an old tank, you wouldn’t have a “high flow toilet”. Why? The jet or siphon holes are simply not big enough. You’ll never get the same amount of water flow in a low flow toilet. Even if you greatly increase the amount of water you flush down the toilet. 

So, is your low flow toilet hopeless? Maybe. If it’s brand new, you’re probably never going to get it to function how you’d like. However, you might be able to take steps to increase water pressure upstairs if you have an upstairs toilet. Or, you might be able to make small adjustments inside the toilet to change the pressure. 

How to Make a Low Flow Toilet Flush Better 

If your low flow toilet isn’t flushing properly, your next steps should depend on how old it is. For example, if you have a brand-new toilet, it wouldn’t make sense to give it a thorough cleaning. If your toilet is old, that should definitely be your first step. 

Clean the Toilet 

Toilets easily lose pressure when dirty or clogged. Giving the toilet a thorough cleaning can help to resolve any flushing issues. That means taking steps to fully soak the toilet to remove any clogs, to decalcify the jet holes, and to clean the tank. 

Bleach – Cleaning a toilet should always start with bleach. This kills the bacteria and makes it safer for you to clean it yourself. Bleach the toilet tank and the toilet bowl. You also want to use a bleach spout to bleach up around the edges of the toilet and in the siphon holes. From there, you should let the bleach sit for 20-30 minutes. Then, flush the toilet repeatedly. 

Vinegar Solution – The second step to cleaning your toilet is to use a vinegar and water solution on the tank and the toilet bowl. You can let this sit for 4-24 hours. Make sure you use the toilet first if you don’t have another toilet. Then, wait as long as possible to flush it again. Vinegar breaks up calcium deposits, which can help to clear out clogs in the toilet mechanism, the bowl, and in the drain. 

Check for Clogs – Use a plunger or drain declogger to remove any clogs that might be in the toilet. This step won’t always be necessary. However, if you have a partially clogged toilet drain or flange, it will cause your toilet to flush less efficiently. 

Clean the Siphon Holes

Cleaning the siphon holes in your toilet should always be done after bleaching your toilet. You’ll also want to soak everything in vinegar first. Then, use a steel fine bottle brush, a straightened coat hanger, or an ice pick to individually clean out the holes around the toilet rim. Insert the cleaner as far into the holes as you can, and then pry it out, attempting to scrape the sides. If there are clogs, calcifications, or built-up debris, getting it out can definitely improve how your toilet flushes. 

You want to make sure you use rubber gloves, even if you’ve already bleached the toilet. 

Raise the Floater

The floater or floater ball controls how much the tank fills with water. Try turning the toilet on and flushing it with the lid off. How far up does the toilet fill? If there’s still plenty of space between the cap and the overflow valve or flow restrictor, you can always raise the floater. This allows more water into the tank, so you flush with (slightly) more water. How do you raise the floater ball? Most are attached using a metal rod. You can easily bend this slightly upwards until it rests at a higher mark on the toilet. 

Alternatively, you can consider actually replacing the overflow valve with one that ends closer to the lid. However, this might risk your toilet overflowing if something goes wrong. You should always keep the water at least a half inch below the lid to prevent accidents. 

Remove Any Flow Restrictors 

In some cases, low flow toilets use a plastic brick or block inside the toilet tank. This allows them to reduce the amount of water in the tank without putting out an absurdly small toilet tank. In some cases, this is built in. In others, you can simply take it out. 

However, depending on the manufacturer, a flow restrictor might be bolted or glued in. You’ll have to check your toilet to see. In this case, the flow restrictor serves the same purpose as the old-fashioned habit of putting a water bottle or a brick in the toilet. It takes up space in the tank so less water can go in. Then, when you flush the toilet, you spend less money on water. 

Check the Flush Handle 

If your toilet’s flush handle isn’t working properly, you’ll always get a poor flush. In this case, you might have to lubricate the mechanism. You might also want to tighten the chain between the handle and the flush valve – in case the flush valve isn’t lifting properly when you flush the toilet. Like the flow restrictor issue, this can occur with new toilets as well. For example, many new toilets ask you to set the flush chain yourself. If it’s too loose, you’ll have a poor flush from day one. However, if it is too tight, your toilet may constantly leak water into the bowl. 

Clean or Replace the Flush Valve 

If you have an old toilet, the flush valve may be dirty, damaged, or broken. Flush valves are made of rubber are make a seal with the bottom of the toilet bowl, over the valve into the bowl. If the flush valve is partially broken, doesn’t’ lift all the way, or allows water to leak out, you’ll have a poor flush. In the case of the first and last option, your toilet tank will never fill all the way up. If water constantly leaks out, you’re simply paying a great deal for water going down the drain without you. 

Luckily, replacing a flush valve is a simple matter of using a pair of pliers to take the rubber plug off the flush chain. You can then take it to any hardware store to buy an identical replacement, likely for a few dollars. 

Increase Water Pressure

In some cases, toilet flushing issues relate to house water pressure. For example, if your water pressure is very low, the toilet tank may not have time to fill all the way up in between usage. That’s especially likely if you sometimes get a good flush and other times just do not. Here, you probably want to check the toilet tank before using the toilet to make sure the tank is full. If it’s not, you might have to increase pressure. 

Water pressure issues are very common on second and third floors. They’re also common if you have a lot of taps or valves using water – especially all at once. You can fix water pressure issues by hiring a plumber to either install a water cistern on your top floor or to install a pump. Both of these can be a significant investment, so make sure you’re ready to invest before opting into either option. 

4 Major Low Flow Toilet Problems 

Low flow toilets can save a lot of money and reduce water waste considerably. However, they also have many problems. 

Pressure-Assisted Systems

Low flow toilets use pressure-assisted systems to flush waste. If the pressure-assisted system isn’t working properly, the rest of the toilet stops working as well. Unfortunately, this mechanism is normally built into the toilet. This means that if your toilet stops flushing properly, you’ll likely have to replace the toilet. Of course, you can always try cleaning the toilet and increasing water pressure in other ways first to make sure that’s the issue. 

Higher Likelihood of Clogs 

Traditional toilets use 8-12 gallons of water to flush the toilet. This means that when you flush waste, it has a significant amount of water to carry whatever you flush out your drainpipes and into the sewers. When you use less water, you’re more likely to leave waste behind as water drops off. That can cause havoc in households accustomed to flushing things that aren’t human waste. It can also result in human waste clogs where water pressure is low. 

If you have a low-flow toilet, it is significantly more likely to clog. That means you’re more likely to need a snake or auger. You’re also more likely to want a plumber to flush your pipes or drains on a regular basis. And, you’re more likely to need a plunger to remove clogs when they happen near the drainpipe or toilet flange. Unfortunately, there’s very little you can do about that except, perhaps, not flushing non-waste items. Some people also choose to avoid defecating in upstairs toilets. However, this can be significantly inconvenient. 

High Water Pressure is Needed

Most low-flow toilets rely on high water pressure and low water volume. If your sewage, your toilet, or your home is not built to accommodate, it can cause problems. That can also mean you have to flush your toilet several times to get a proper flush. This completely voids the point of using a lower volume toilet to flush waste. 

They Can Be Expensive to Install 

If you have an older home, installing a low-flow toilet can be significantly expensive. Why? You might have to replace the water pipes, drainage, and other connections in your home. Low flow toilets normally require plumbing to be set at a specific angle to maintain the kind of pressure and vacuum needed for them to work. That’s easy enough if your home has been built in the last two decades. If it’s older, installing your low flow toilet properly might involve considerable adjustment to your plumbing. 

Most importantly, if you’ve installed a low-flow toilet yourself and are now having issues, it could be that your plumbing is set at the wrong angle. You can always check with a professional plumber to ask their advice if that might be the case. If so, the only solution is to adjust the plumbing to the right angle and slope. 

Are High Flow Toilets Worth It? 

High flow toilets use a considerable amount of water. In addition, they’re also illegal in some states. For example, the state of California mandates that homeowners installing a new toilet not install one using more than 1.28 gallons of water. Other states have no such regulations in place. However, it is true that it is increasingly difficult to even find high flow toilets. That’s fair, considering low flow toilets normally work just as well as low flow toilets. If you’re having problems, those problems likely stem from clogs, poor installation, or unsuitable plumbing. They’re also likely very fixable. Unfortunately, some homes also just have very low water pressure. This can be difficult to fix without significant changes to the home. On the other hand, installing a high flow toilet won’t always solve that problem. 

Frequently Asked Questions

Solving problems with low flow toilets is never easy. Chances are, you still have questions. 

Can I convert my toilet to a power flush system? 

In most cases, you can install a power flush system in your toilet tank. However, you should check that it is compatible with your model first. Power flush systems use an air bladder to force water through the siphon holes more quickly, so they flush the toilet bowl better. This moves anything in the bowl into the drain faster, removing any issues you might have with poor waste removal. 

However, not all toilet siphon systems are compatible with power flush conversions. If you do decide to install a power flush converter into your toilet, make sure it’s rated for your toilet tank size. Then, follow the instructions on the package to install it. In most cases, you’ll have to take the toilet mechanism apart, install the air bladder, and thread the air bladder’s hose up through the toilet’s water supply. Most conversion kits will include visual guidance to reduce any confusion. 

Are low flow toilets good? 

Low flow toilets are normally as good as a traditional toilet. That’s why they are the most commonly sold toilet. They can also significantly reduce water usage and therefore your water bill. This can help you to meet personal targets for being eco-conscious. It can also help you to meet water restriction requirements during a drought. Or, it can cut down on your energy bill. 

However, you may also have some problems with them. For example, in some cases, you may have to flush the toilet twice. This can be unpleasant, especially if you don’t notice it at first. In other cases, you might have to deal with a more frequent occurrence of clogs and issues. This can also be unpleasant. However, on average, low flow toilets are comparable to normal toilets. 

How much water can you save with a low flow toilet? 

Low flow toilets can use as little as 1.2 gallons of water to flush a toilet. That’s just 10% of a large, traditional toilet, which can use 12. That means saving up 6-10+ gallons of water every single time you flush your toilet. The more people you have in your home, the more that adds up. The average person in the United States flushes a toilet 5 times per day. That means you could save over 50 gallons of water, per day, per person. And, that can really add up. 

To Finish

Low flow toilets are environmentally friendly and sometimes required by law. At the same time, they can be an inconvenience. Hopefully, these tips help you with your flushing and pressure issues.