When searching for a home, you might find one with a grinder pump attached to its sewage system. A grinder pump is not necessarily a red flag, but it comes with some additional commitments you should be aware of.
Key takeaways from this article:
- Grinder pumps are used when wastewater must be pumped uphill or to a pressurized sewer main because gravity can’t do the job
- You can’t use a grinder pump with a septic tank.
- Buying a house with a grinder pump can be a good choice if it’s well-maintained and necessary for the property.
Is a grinder pump a deal breaker?
Grinder pumps are not automatically a deal breaker in home sales unless they have significant repair issues. Grinder pumps are sometimes necessary for proper sewer functioning, so if you are really set on a specific property, a grinder pump might be a required fixture.
As long as a sewage grinder pump is regularly maintained, you shouldn’t notice it during normal functioning. Many experts agree you should get a professional inspection at least once every three to five years.[1]
The main downside is the increased maintenance costs and responsibility for repairs. As the homeowner, you’ll assume full responsibility for the grinder pump, which may represent an unnecessary risk to some buyers.
Overall, a grinder pump system is not a deal-breaker if you are willing to shoulder repair and maintenance costs and are set on a property where it's necessary.
What’s a grinder pump?
A grinder pump is a special type of sewage pump that uses special blades to grind sewage up and pump it into the main sewer line.
Grinder pumps consist of a basin that collects wastewater from your home’s sewage. A special motor spins an impeller that liquifies solid waste before a discharge system pumps the waste to the main sewer line.
You can think of a grinder pump as similar to a giant garbage disposal for your sewer instead of your kitchen sink. The average grinder pump is about two feet in diameter and installed underneath the concrete foundation.
Grinder pumps differ from gravity sewer systems, which use natural gravity to flush wastes through pipes rather than an actual pump.
Grinder pumps are more common in commercial buildings that need to process significant amounts of waste, but they can also be installed in homes that are located below the main sewer line.
Why some homes have grinder pumps
Grinder pumps are necessary in homes that have their plumbing located below the sewer line. Because sewage for the house is below the sewer line, you can’t rely on gravity to flush the system. Instead, a grinder pump moves the wastewater up so that it can properly drain into the sewer.
As such, grinder pumps are common for fixtures like basement bathrooms and kitchens that exist below ground. Grinder pumps have a head height,indicating how high they can raise sewage. A grinder pump's head height needs to be large enough to vertically lift wastewater to the nearest sewer line.
Grinder pumps may also be necessary if terrain restrictions prevent typical sewer arrangements. For example, homes that are located far from municipal sewers may need grinder pumps to transfer wastewater over large enough distances to reach the sewer lines.
Grinder pump vs. ejector pump: Which do you need?
Grinder pumps are similar to ejector pumps in that they both pump sewage up a vertical distance to connect to the main sewer line.
However, ejector pumps don’t have blades and instead use a spinning impeller to push waste through the pipes.
The main differences between the two come down to utility and cost. Grinder pumps are better for processing solids and are better at moving waste a further distance.
Ejector pumps are less expensive and could be better for shorter-distance plumbing.
Grinder pumps are necessary only when an ejector pump won’t work. Grinder pumps also cannot be used with septic systems because the fine slurry prevents the tank from properly filtering wastewater.
In the context of commercial rental units, landlords should generally avoid buying units that require a grinder pump.
They are useful for processing more waste, but landlords can’t necessarily control what tenants flush down their pipes (e.g., wet wipes, hygiene products, etc.).
Pros and cons of buying a house with a grinder pump
As with any home purchase, there are pros and cons to buying a house with a grinder pump installed.
Pros
- Enable sewer connection
- Reliable when used correctly
- Typically not noticeable
Cons
- Higher upfront cost
- More sensitive to misuse
- Mechanical failure risk
The main benefit of a grinder pump is that you can connect your home’s wastewater lines to the sewer when gravity alone won’t cut it. This allows more flexibility with house construction and room layout.
Grinder pumps are extremely reliable when used correctly and maintained properly. The typical grinder pump can last up to 15 years without significant issues. Unless there is a repair issue, you shouldn’t notice the grinder pump when it's in operation.
Because they are a separate fixture, a grinder pump can result in higher upfront costs when buying a house.
Flushing improper waste, like wet wipes or hygiene products, can cause grinder pumps to clog. Grinder pumps have a lot of moving parts and so are more at risk of mechanical failure than traditional gravity-based sewer systems.
How much do grinder pumps cost?
You can split the costs of a grinder pump down into three categories:
- Installation: $2,000–5,000
- Operation: $30–50
- Maintenance: $200-375
Below is a more detailed breakdown of each category of expenses
1. Installation
Installation is the most expensive cost of owning a grinder pump and typically amounts to between $1,500 and $5,000.[2]
A significant chunk of that amount is labor costs, which can vary heavily depending on local factors. It usually takes about six hours to install a grinder pump, but it can take longer if your sewer line is difficult to access.
2. Operation
Installation is expensive, but operating a grinder pump is much more affordable. Operation costs usually total between $30 and $50 per year — about the cost of a standard 40w light bulb.[2]
Because they operate in short bursts, grinder pumps are not a major drain on electrical power.
3. Maintenance
Grinder pumps need regular servicing, which typically costs between $200 and $300 a year. However, maintenance costs can vary based on which parts need fixing.[3]
Repairing broken blades, for example, will cost more than cleaning the wastewater reservoir.
A new grinder pump typically lasts up to 15 years before experiencing problems, assuming regular care and maintenance. So, if you are buying a home with an older grinder pump, you may have to budget for new installation costs sooner rather than later.
Common grinder pump problems
Grinder pumps are not risk-free, and problems can arise that affect your plumbing.
As long as you are maintaining the system correctly and not flushing foreign objects, you shouldn’t have frequent grinder problems.
However, various factors out of your control can cause repair issues that need to be addressed, so it’s best to be prepared.
Here are some common problems that are associated with grinder pumps and how to solve them.
Clogging from objects
The most pressing problem with grinder pumps is clogging from foreign objects. Grinder pumps can handle most solid waste, but they can’t handle foreign objects made from cloth or cotton.
Power outages
Since they run on electricity, grinder pumps will not work during power outages.[4]
As such, many homeowners purchase backup generators to run the pump if the power cuts off.
Alarm activation
Grinder pumps have a maximum volume of fluid they can process at once. If the water goes over a certain level, it will trip an alarm and shut off the pump to prevent overflowing and clogging.
Wear and tear
The grinder pump will naturally accumulate wear and tear through use, particularly the impeller blades that grind up solid waste.
What you can and can’t flush with a grinder pump
The two things you can flush down a grinder pump are human waste and toilet paper. Even then, flushing too much toilet paper can cause clogs, so you shouldn’t overload your pipes.
Anything that won’t break down organically isn’t suitable to flush down a grinder pump. This includes things like wet wipes, paper towels, hygiene products, diapers, hair, fats, oils, and grease.[5]
These substances will snag on the blades and clog the system, causing severe backup and requiring expensive repairs.
Flushing inappropriate objects will not only require immediate repairs but will also impact the long-term health of your system. In other words, misuse directly leads to additional repair and replacement costs.
Flushing only appropriate objects will keep the system clear and prevent unnecessary wear and tear on the blades and pipes.
Should you buy a house with a grinder pump?
Whether or not you should buy a house with a grinder pump depends on the circumstances.
Ask yourself the following questions before committing to the purchase:
- Does the property require a grinder pump for the plumbing to work properly? You generally should avoid a grinder pump unless it’s necessary to connect to the main sewer line.
- Is the system working properly and well-maintained? Buying a house with a well-maintained system will prevent unexpected repair and replacement costs.
- Are you comfortable with handling maintenance? Grinder pumps aren’t exactly hands-on, but you will need to schedule and pay for regular maintenance and cleaning, as well as budget for eventual replacement.
- Are you buying a single-family home or a multi-unit property? With multi-unit properties, it can be hard to prevent all occupants from flushing foreign objects that could cause damage.
How an agent helps protect you
Having a knowledgeable real estate agent on your side can help you make the right decision concerning buying a house with a grinder pump system.
An agent can help answer inspection questions and help you understand local sewer regulations and whether a grinder pump is necessary for the property.
Most importantly, your agent can negotiate repair credits and seller concessions at the sale if there are pre-existing issues.
By using Clever, you can search for local top agents in your area who are experienced with inspections and negotiations. You may also qualify for cash back at closing!
FAQ
What does a grinder pump do?
A grinder pump grinds raw sewage into a fine slurry and pumps it to a pressurized sewer main. It’s basically a garbage disposal, but for your sewer instead of your kitchen sink.
Why do houses have grinder pumps?
Homes have grinder pumps when they need to move waste uphill or across long distances. For example, basement bathrooms may need a grinder pump to move sewage up if it’s oriented below the main line.
How long does a grinder pump last?
The typical grinder pump can last up to 15 years, assuming regular maintenance and repairs.
Are grinder pumps loud?
A properly functioning grinder pump should not be loud and should only make a low humming sound under operation. Loud grinding, rattling, or buzzing sounds are typically indicators of repair issues.