PEX is cross-linked polyethylene tubing used for hot and cold water supply in homes. It is flexible, needs fewer fittings than rigid pipe and does not corrode the way metal can. A repipe with PEX is often quicker than copper, and it is a common choice for remodels and whole-house repipes.
It is not a free pass, though. Fittings, supports, sun exposure and the way it connects to a water heater all matter. Call (860) 397-8103 if you want a plumber to look at a repipe, and you get a clear price before work starts.
PEX A, B and C compared
The letters describe the manufacturing method, not quality grade. Each type behaves differently on the job.
| Type | Flexibility | Common fittings | Notes |
|---|---|---|---|
| PEX-A | Most flexible, recovers from kinks | Expansion rings, cold expansion | Strong joints, often easier to work in tight runs |
| PEX-B | Stiffer, holds a bend | Crimp or clamp rings | Common, widely stocked, good value |
| PEX-C | Between A and B in feel | Crimp rings | Less common, check availability and listings |
Fittings: crimp, clamp and expansion
Crimp and clamp fittings use a metal ring squeezed around the pipe on a barbed insert. Expansion fittings stretch the pipe and ring, then the pipe shrinks back onto the fitting. Push-to-connect fittings exist too and are handy in repairs, but are usually costlier.
What to check on any PEX job
- Pipe and fittings should be listed to NSF/ANSI 61 for drinking water contact, and the pipe should be marked.
- Use fittings made for the same system and brand, with the correct tool and gauge.
- Support the pipe at the intervals the maker specifies so it does not sag or rattle.
- Keep PEX out of long sun exposure. Ultraviolet light degrades it, so cover or limit time outdoors.
- Keep PEX away from recessed lights and flue pipes, and use metal or approved connectors at the water heater.
- Use sleeves where pipe passes through framing, so it does not rub.
- Test the system under pressure before closing walls.
PEX and freezing
PEX tolerates freezing better than rigid pipe because it expands somewhat when water turns to ice. That does not make it freeze-proof. Fittings and brass connections can still split, and a frozen line still blocks water. Insulate lines in unheated spaces, and keep PEX away from exterior walls where you can.
If a line freezes or bursts, shut the main supply and call. Our burst pipe repair page covers what to do.
PEX near the water heater
Do not connect PEX directly to a hot water heater outlet unless the manufacturer allows it. Use the connector the instructions require, often a short metal nipple, because tank outlets can run very hot.
How a PEX repipe usually goes
Plan the layout
The plumber decides between a trunk and branch layout or a home-run manifold, and where access holes and shutoffs go.
Shut off and drain
The main is closed and the system drained so old pipe can come out safely.
Run the new lines
PEX is pulled through walls, floors and basements with fewer joints than copper.
Make connections
Fittings are crimped, clamped or expanded. Each joint is checked with a gauge or inspection tool.
Pressure test and patch
The system is tested before drywall is closed. Wall repairs are usually a separate trade.
What affects the cost of a PEX repipe
The pipe is cheap. Access and layout drive the price.
What moves the price
- Size of the home and the number of fixtures.
- Access: open basements are easier than finished walls and slabs.
- Layout: manifold systems use more pipe but fewer joints.
- Fittings brand and system, and whether valves are added at fixtures.
- Drywall, paint and patching, which are often separate.
- Timing: nights and weekends are priced differently from a weekday.
Call (860) 397-8103 for a clear price before work starts. See our repiping service for scope.
Rocky Hill water and pipes
MDC's 2025 water quality report says corrosion control is used to bring pH above neutral, with an average pH of 7.41. MDC also reports that it uses no lead pipes in its distribution system. Those facts concern the utility's mains, not the pipes inside your home.
Your service line and interior plumbing are your own to check. MDC publishes a Water Service Line Inventory and guidance on identifying your service line. Most Rocky Hill homes date from 1960 to 1990, so older interior supply pipe is worth looking at if you plan a repipe.
Source type: water utility quality report and town planning document
Common PEX mistakes
- Mixing brands of pipe and fittings that are not meant to work together.
- Using the wrong crimp tool or skipping the go and no-go gauge.
- Leaving PEX in sunlight for long periods before it is covered.
- Tight bends that kink the pipe.
- Skipping supports, which causes sagging and water hammer noise.
- Connecting PEX straight to a hot heater outlet.
- Not pressure testing before closing walls.
Next steps
If you are replacing old supply lines, our plumbing installation page covers new lines and remodel rough-in. We serve Newington and Cromwell too.
Questions homeowners ask
What is the difference between PEX-A, PEX-B and PEX-C?
The letters describe the manufacturing method. PEX-A is the most flexible and uses expansion fittings. PEX-B is stiffer and usually uses crimp or clamp rings. PEX-C sits between them. All are used for water supply when installed to the maker's instructions.
Is PEX safe for drinking water?
PEX intended for potable water should be listed to NSF/ANSI 61 and marked on the pipe. Use only listed pipe and fittings, and follow the manufacturer's instructions.
Will PEX burst if it freezes?
PEX is more tolerant than rigid pipe, but it is not freeze-proof. Fittings can still split. Insulate exposed lines, and shut the supply and call if a line freezes.
Can PEX go outdoors?
Not for long. Sunlight damages PEX, so keep it covered and limit exposure during installation. Use approved materials for outdoor lines.
Do I need a permit to repipe with PEX in Rocky Hill?
Ask the Rocky Hill building department. Permits are handled through the town's portal and Building Department. Do not assume a repipe is exempt.
Is a PEX repipe better than copper?
It depends. PEX is faster to install and handles tight runs, but copper has a long track record. The best choice depends on your home, budget and plumber's recommendation.
Call the 24/7 line, describe the problem, and we confirm what it will cost before any work starts.