Frequently Asked Questions
Products
Quick Answer: Merrill well seals come in multiple materials, sizes, and configurations to fit both steel and PVC well casings. Choosing the right one depends on your casing’s inside diameter (ID), pump type, and installation needs.
Types of Well Seals We Offer:
1. Materials:
- ABS Plastic – Strong, durable, and highly chemical-resistant. Increasingly popular for modern installations.
- Cast Iron – Powder-coated for corrosion resistance and long-term durability in outdoor environments.
- Steel-Top Models – Thinner top made from steel for certain applications.
2. Configurations:
- Solid Well Seals – One-piece design.
- Split Well Seals – Two-piece design for easier installation around existing drop pipe.
- Single Drop – For standard submersible pump installations.
- Double Drop – Required for jet pump setups (allows for both downpipe and return pipe).
Key Sizing Considerations:
- Casing Material: Works with both steel and PVC casings.
- Inside Diameter (ID): Always measure your casing’s actual ID. PVC casings vary in wall thickness depending on type (e.g., SDR 17), which affects the ID and proper well seal fit.
- Lip Fit: The seal’s top lip must sit securely on the casing, and the gasket must compress properly against the ID when bolts are tightened.
Installation Features:
- Thick gasket compresses around both the inside of the casing and the drop pipe for a secure fit.
- Conduit hole for electrical wiring and a separate vent hole to allow the well to breathe.
- Cast iron models include grommets for conduit to ensure a tight seal.
Special Notes:
- Not for artesian wells – these seals are not designed for continuous water flow from artesian pressure.
- UV Resistance: ABS and powder-coated cast iron are resistant to sun exposure.
- Drop Pipe Size: Available for different pipe sizes; choose the correct size for your application.
With the right material, configuration, and size, Merrill well seals provide a durable, secure fit for a wide variety of well installations.
Resources:
Quick Answer: Merrill pitless adapters are built from high-quality materials and sized to match your installation needs. The correct model depends on the weight of your pump, drop pipe, and water column—measured in feet of pipe, not pounds. All Merrill pitless adapters meet Water Systems Council standards for safety and durability.
Understanding Pitless Adapter Weight Ratings:
- Ratings are in feet of pipe – not pounds.
- Example: 1" steel pipe (filled with water) weighs just over 2 lbs per foot.
- If a model is rated for 300 ft, the combined weight of your pump, pipe, water, and wire cannot exceed that equivalent.
- Always use Merrill’s published ratings, which follow Water Systems Council standards—some competitors list higher ratings by not adhering to these guidelines.
Durability & Leak Protection:
- Thick O-ring plus a gasket for a secure, watertight seal.
- Recessed interior O-ring ensures tight sealing inside the casing.
- Discharge fitting covers the drilled casing hole completely, with a collar and nut for added security.
- Designed to prevent leaks at the casing entry point, even under long-term use.
Choosing the Right Model:
- Determine your total load: pump weight + drop pipe weight (with water) + wire.
- Match this load to Merrill’s published feet-of-pipe rating for the adapter size.
- Select a model that meets or exceeds your installation’s weight and size needs.
Merrill offers a wide range of pitless adapters to accommodate different well depths, pipe sizes, and installation requirements—all built to the highest quality standards.
Resources:
Quick Answer: Check valve chatter is usually caused by a problem with the pressure tank—not the valve itself. If your tank has lost its air cushion, the pump will cycle on and off rapidly, making the check valve open and close repeatedly.
Why It Happens:
- In a healthy pressure tank, water compresses an air cushion separated by a diaphragm or bladder.
- If the diaphragm ruptures or tears, the water absorbs the air, eliminating the cushion.
- Without that cushion, pressure drops quickly after each pump cycle.
- The pump turns on and off rapidly, causing the check valve to “chatter” as it repeatedly opens and closes.
How to Fix It:
- Inspect the pressure tank for a ruptured diaphragm or bladder.
- If damaged, repair or replace the tank to restore proper air volume.
- Once the tank is functioning properly, the chattering should stop without replacing the check valve.
Resources:
Quick Answer: Most check valve failures are caused by debris, sand, or sediment entering your water system—not by a defect in the valve. Filtering the water before it enters the system can greatly extend valve life.
Why It Happens:
- Any debris in the water source will travel through the plumbing and collect at points of restriction.
- The check valve is one of the first such restrictions, making it a common place for buildup.
- Over time, this debris prevents the valve from sealing or operating correctly.
How to Prevent It:
- Install a filter or sediment trap before the check valve to catch debris from the water source.
- Regularly inspect and clean filtration systems.
- Address the source of contamination (well screen issues, damaged intake, etc.).
- Remember: Debris also damages faucets, showerheads, and other fixtures, so solving it benefits the entire plumbing system.
In both cases, the issue often isn’t the check valve itself—solving the underlying problem (tank or water quality) is key.
Resources:
Quick Answer: A check valve is designed to allow water to flow in one direction and prevent backflow, protecting pumps and other equipment.
How It Works:
- Inside the valve, a poppet opens when water flows forward and closes when water stops or reverses.
- This prevents reverse flow that could damage pumps or contaminate water systems.
- Merrill check valves are built to operate both vertically and horizontally (with some recommendations for certain sizes—see below).
Installation Tip:
For valves 1¼" or larger, use a variable flow design with internal ribs. These ribs guide the poppet to prevent it from sticking or getting misaligned in horizontal installations.
Resources:
Quick Answer: Use a variable flow check valve—especially in sizes 1¼" and larger—for horizontal installations or when you want maximum efficiency and reduced friction loss.
Benefits of Variable Flow:
- Has internal ribs to keep the poppet aligned, preventing sticking.
- Features a poppet within a poppet:
Small poppet opens for low flow, reducing friction loss.
Suitable for deep well installations—tested in applications as deep as 1,000 feet with heavy-duty models.
Resources: - Helpful Videos
- Youtube Channel
- Distributor Map- Find Your Distributor Near You
- Helpful Resources - Documents
Quick Answer: Merrill check valves are available in no-lead brass, bronze, and stainless steel. Choose based on installation environment and corrosion risk.
Material Options:
- No-Lead Brass: Standard for most residential and light commercial use.
- Bronze: Higher copper content; stronger and more corrosion-resistant. Recommended for buried or corrosive environments.
- Stainless Steel: Extremely durable, corrosion-resistant, and available in variable flow models. Best for demanding applications.
Future Availability:
Variable flow models currently available in stainless steel. Bronze and ductile iron versions will be available soon.
Selecting the right material ensures long service life and reliable performance for your system.
Resources:
Quick Answer: Merrill splice kits include a high-quality heat shrink sleeve with both adhesive and sealant inside, plus a solid-core crimp connector. This ensures a secure, watertight electrical connection that won’t slip or fail—ideal for underground and submerged applications.
How to Install a Merrill Splice Kit:
- Slide the heat shrink sleeve over one wire before making the splice.
- Insert wire ends into the crimp connector and crimp securely.
Merrill connectors have no seams, so you can crimp more than once without splitting. - Center the sleeve over the crimp connector so it fully covers the splice.
- Apply heat (torch or heat gun)—use the heat, not the flame.
Start in the center, shrink around the crimp, then work toward each end. - Look for the seal bead
Why Merrill Splice Kits Are Better:
- Adhesive + Sealant inside the sleeve for both sealing and bonding.
Many cheaper sleeves have only sealant, allowing the sleeve to slide off if snagged. - Solid-Core Crimp Connectors – no seams, won’t split, maintain strong tension on wires.
- Clear or Black Sleeves available:
- Clear: Lets you see the crimp, wire engagement, and seal quality—easier to confirm a perfect job.
- Black: Traditional choice many contractors prefer out of habit.
- Multiple sizes for different wire gauges, plus bulk lengths and tubes available.
- Proven in decades of contractor use—works reliably in buried or fully submerged environments.
Merrill was one of the first companies to introduce heat shrink splice kits to the industry, recognizing their superior performance over older connection methods.
Resources:
Quick Answer: A drive well point is a screened intake at the bottom of a driven well system. Merrill offers drive well points in 1¼" and 2" sizes, with cast iron tips for penetrating soil and stainless steel mesh screens to allow water entry. The correct performance and depth depend on your soil conditions, water table, and pump type.
Key Features:
- Cast Iron Point – Designed to penetrate soil during installation.
- Stainless Steel Mesh Screen – Surrounds the intake area to allow water flow while preventing debris entry.
- Two Sizes Available – 1¼" and 2".
- Threaded End – For attaching galvanized pipe during installation.
Water Production Capacity:
Exact gallons per minute (GPM) cannot be guaranteed—it depends on water table depth, recharge rate, soil type, and pump style.
General guideline: Approximately 3 GPM per square inch of screened surface area. Longer screens provide greater potential capacity.
Installation Tips:
1. Use a true drive cap on top before pounding to protect threads—never pound directly on the pipe threads.
2. Attach galvanized pipe in sections as you drive deeper.
3. Always use a proper drive coupling between pipe lengths to prevent thread damage.
4. Drive through suitable soils such as sand, loam, or clay (avoid compacted rocky layers or solid rock).
Soil Considerations:
- Can be driven through sand, loam, or some clays.
- Avoid overly compacted, rocky, or solid stone layers.
- Depth required depends on your specific site conditions and the location of the water table.
Merrill drive well points are built for durability in demanding environments, combining a strong cast iron tip with corrosion-resistant stainless steel screening.
Resources:
Quick Answer: Merrill pitcher pumps can pull water from depths up to 25 feet and are available in two models—a standard and a heavy-duty version. With proper installation and occasional priming, they provide reliable, hand-operated water access.
Key Performance Facts:
- Maximum Lift: 25 feet for both models.
- Priming:
- Frequent use usually keeps the pump primed.
- If the pump sits unused for a long period, pour water into the priming hole to moisten the internal cup leather before use.
Compatibility:
Works with 1¼" drop pipe—just use a reducing bushing to connect to the pump’s inlet.
Model Differences:
1. Heavy-Duty Model:
- Thicker casting for added durability.
- Handle shape is considered more ergonomic by some users.
- Uses a rubber-like cup instead of traditional leather.
- Features an embossed phrase meaning “Continual Triple Success,” adding a unique decorative touch.
2. Standard Model:
Traditional design with actual leather cup inside.
Applications:
Ideal for gardens, decorative installations, rural water access, and emergency backup water retrieval (within depth limits).
Whether you choose the standard or heavy-duty version, Merrill pitcher pumps are built for dependable performance and long service life.
Resources:
Navigation
There are a few methods to find a product.
- Search by entering the product SKU by clicking the magnifying glass in the top right of the site.
- Choose the category that your product belongs under from the available tabs at the top in the navigation bar.
- Contact us if you find an issue with a product, such as no present picture or no listing.
Hydrants
Yes! All Merrill yard hydrants—both older and newer models—are designed so you can service them entirely from above ground. You can replace the head, plunger, and other internal components without any excavation.
How It Works:
Merrill hydrants are engineered with a removable head and rod assembly. This means you can access the internal parts by simply unthreading the head from the standpipe—no need to dig up the hydrant.
Step-by-Step Plunger Replacement Example:
- Shut off the water supply and relieve pressure by opening the hydrant.
- Mark the alignment:
Place tape just under the head casting and make a mark. This ensures you can reassemble it to the correct adjustment. - Remove the head casting using two wrenches—one on the head, one on the pipe.
- Pull out the rod and plunger from inside the standpipe.
- Replace the plunger by unscrewing the old one and installing the new one.
- Optional but recommended:
Briefly turn the water back on (with the rod removed) to flush out any debris from the valve body. - Reinstall the rod and head, aligning it with your tape mark for proper operation.
Why This Matters:
- Saves time and labor—no trenching or digging required
- Keeps repairs simple, even in winter or frozen ground conditions
- Extends the life of your hydrant with minimal downtime
In most cases, replacing the plunger and flushing the hydrant solves the problem—all without disturbing the ground.
Resources:
If your yard hydrant handle suddenly becomes hard to lift, it’s often a simple fix. In most cases, the cause is a pinched O-ring under the packing nut where the operating rod passes through.
Why This Happens:
- The packing nut may have been overtightened.
- Over time, the O-ring can shift and pinch between the packing nut and rod.
- This creates extra friction, making the handle harder to move.
Quick Fix:
- Locate the packing nut just below the handle.
- Using a wrench, turn the nut about ¼ turn counterclockwise (loosen slightly).
- This small adjustment raises the nut enough to unpinch the O-ring.
- Test the handle—it should now move freely.
Note:
If the issue happens during freezing weather, the problem may be ice-related. That’s a different cause and solution (covered in a separate FAQ).
This quick adjustment usually resolves the stiffness instantly—no part replacement or digging required.
Resources:
Quick Answer: Your hydrant may be freezing because the plunger is out of adjustment, sitting too high in the valve body. This prevents water from draining out of the hydrant after it’s shut off, allowing it to freeze in cold weather.
Why It Happens:
A frost-proof hydrant works by draining water out of the standpipe into the ground below the frost line after use. If the plunger is misaligned or worn, it can block the drain hole in the valve body. When that happens, water stays in the pipe—and in freezing temperatures, that water will turn to ice.
How to Check If Your Hydrant Is Draining Properly:
- Fill a cup with water and hold it against the spout.
- Push the handle down to shut off the hydrant.
- Watch the water in the cup: If it completely siphons back into the hydrant, it’s draining properly.
- If water remains in the cup, your plunger needs adjustment or replacement.
How to Fix It:
- Adjust the plunger to the correct position in the valve body.
- If the plunger is damaged or worn, replace it.
- Both adjustments and replacements can be done without digging up the hydrant.
Get Step-by-Step Instructions:
Visit our Resources--->Helpful Videos page and watch our repair videos for detailed instructions on adjusting or replacing your plunger.
Proper adjustment ensures your hydrant drains completely after each use—preventing costly winter freeze-ups.
Resources:
Quick Answer: Yes. In almost every case, the same parts kits we sell today will work on older Merrill hydrants—even models built decades ago.
Why This Works:
Merrill hydrants are designed for long-term serviceability. For example, the AnyFlow® model has been in production since 1949 with no major design changes that affect part compatibility. The only updates made over the years are:
- Plunger material upgrade – Older plungers used leather cup seals; today’s plungers use a stronger, longer-lasting material.
- Handle design improvement – The handle opening is now larger and more rounded to make operation easier with gloved hands.
Special Note on the AG4000 Model:
- This model was discontinued over 26 years ago.
- It can be identified by the head being held on with set screws instead of threading onto the standpipe.
- Not all current parts are compatible, but plungers are still available because they are also used in another Merrill model.
- Other heads cannot be threaded onto the AG4000 standpipe.
Bottom Line:
- For nearly all other Merrill hydrant models, you can purchase any current parts kit that matches your model, and it will fit—no matter the year it was made.
Need Help Finding the Right Kit?
Visit our Parts page or contact our sales team for help identifying your model and the correct parts.
This commitment to compatibility is one reason Merrill hydrants have been trusted for generations.
Resources:
Quick Answer: If a hydrant sits unused for years, the rubber on the plunger can seize to the valve body. When you lift the handle, the rubber may tear off and stay lodged inside, blocking water flow.
Why It Happens:
- Merrill plungers are made from self-lubricating material that stays flexible when used regularly.
- If unused for years, the rubber can dry out and bond to the inside of the valve body.
- When you try to operate the hydrant, the rubber may separate from the plunger and remain stuck, preventing water from passing through.
How to Fix It:
- Turn off the water supply.
- Remove the head assembly by:
- Placing one wrench on the hex of the head casting and another on the standpipe.
- Turning the head counterclockwise to lift it (with rod and plunger attached) out of the standpipe.
3. Inspect the plunger:
If the rubber is missing, it’s likely lodged in the valve body.
4. Try to dislodge the rubber:
- Turn the water back on briefly to see if water pressure pushes it out.
- If not, use a 3/8" lag screw welded to a rod to screw into the rubber and pull it out.
5. If these methods fail, the only remaining solution is to dig up the hydrant and replace it.
Important:
This issue is rare and usually only occurs when a hydrant is left unused for many years. Regular operation keeps the plunger lubricated and prevents seizing.
Resources:
Quick Answer: Leaks can occur in several areas of a yard hydrant, most often due to sediment under the plunger, worn parts, or a simple out-of-adjustment condition. Nearly all leak issues can be fixed from above ground—no digging required.
Common Leak Locations & Causes:
1. Valve Body (Underground at the Base)
Cause: Sediment or small debris works through the waterline and gets trapped under the plunger seat.
Symptoms:
- Water leaking out of the 1/8" drain hole in the valve body.
- In severe cases, water may travel up the standpipe and drip from the nozzle.
Fix: Remove the head, turn the water on briefly, and flush out debris following Merrill’s detailed flushing instructions.
2. Plunger Wear or Misadjustment
Cause: Over time, the plunger wears down or the pivot connector/set screw becomes misaligned.
Fix:
- Remove the handle, drawer straps, and packing nut.
- Do not dig out the old packing—place a shortened new packing gland (from a repair kit) on top of the old one, reassemble, and tighten.
- Avoid over-packing to prevent handle stiffness.
Pro Tip: All of these repairs can be done from above ground—there is no need to dig up the hydrant for these issues.
Resources:
Quick Answer: If your yard hydrant keeps running or drips from the nozzle after shutting it off, the plunger likely isn’t seating fully. This is usually fixed with a simple above-ground adjustment—no digging required.
Why It Happens:
Over time, the operating rod can get slightly out of adjustment, preventing the plunger from sealing tightly in the valve body. This leaves a small gap where water can continue to flow.
How to Fix It:
1. Turn off the water supply before beginning any adjustments.
2. Remove the lever: Loosen the bolt holding the handle, then remove the jaw straps.
3. Adjust the pivot connector:
- Loosen the two nuts securing the pivot connector.
- Move the connector up slightly to increase the rod’s downward stroke.
- Make small, incremental adjustments—just enough to improve the seal.
4. Tighten the nuts back to the pivot connector.
5. Reassemble the handle and jaw straps.
6. Test the hydrant to ensure it shuts off completely without over-tightening the plunger.
Pro Tip: Always make small adjustments and test between each one. Over-adjusting can compress the plunger too much, causing premature wear or making the handle hard to operate.
Resources: