Short answer: Press fittings are the fastest and safest choice for most copper heating and water work: each joint takes seconds, needs no flame and is consistent from one fitter to the next. Solder (capillary) fittings cost the least per joint but need a torch, lead-free solder on drinking water and time to clean and flush. Compression fittings need only spanners, so they suit repairs and appliance connections, but under the Water Fittings Regulations a joint that may need maintaining must not be concealed or buried in a wall or solid floor.
All three methods make sound joints on copper tube when you fit them properly. The right one depends on the job: how many joints you are making, whether you can use a flame, where the joint will end up and how much you want to spend on tools.
This guide compares them side by side, with real costs from the MaxHeatUFH M-press range, so you can decide which to carry on the van and which to keep for special cases.
What is the difference between press, solder and compression fittings?
The difference is how the seal is made. A press fitting has an O-ring inside each end, and a press tool squeezes the fitting onto the tube so the O-ring and the metal grip it permanently. A solder fitting is a copper sleeve that you heat with a torch so molten solder is drawn into the narrow gap between tube and fitting. A compression fitting uses a brass nut and a soft olive that is crushed onto the tube as you tighten the nut.
| Method | How it seals | Standard |
|---|---|---|
| Press | O-ring, pressed | BS EN 1254-7 |
| Solder | Solder in a capillary gap | BS EN 1254-1 |
| Compression | Nut and olive | BS EN 1254-2 |
All three are made for copper tube to BS EN 1057, the standard for copper tube in water, gas and heating work. Check the tube and fitting are both marked for the job before you start.
Which copper fitting is best for each job?
For new first-fix pipework with many joints, press is usually best. For the odd repair where you have no press tool, use compression where the joint stays accessible, or solder where you can safely use a flame. This table gives a quick steer.
| Job | Best fit | Why |
|---|---|---|
| Full heating or water first fix | Press | Fast, no flame |
| Occupied home, timber floors | Press | No fire risk |
| Wet pipe, can't fully drain | Press | Solder won't take |
| Single repair, no tool | Compression | Spanners only |
| Tap or valve tail | Compression | Easy to undo |
| Lowest cost per joint | Solder | Cheapest fittings |
| Joint under a floor or in a wall | Press or solder | Not a maintained joint |
How much do copper press fittings cost compared with solder?
Press fittings cost more per joint than solder fittings, but the gap is small next to labour. MaxHeatUFH copper M-press fittings are sold in full bags and boxes. These prices are inc VAT, October 2026.
| Fitting (bag) | Bag price | Per fitting |
|---|---|---|
| 15mm coupling (10) | £14 | £1.40 |
| 15mm elbow (10) | £18 | £1.80 |
| 15mm tee (10) | £29 | £2.90 |
| 22mm coupling (10) | £20 | £2 |
| 22mm elbow (10) | £31 | £3.10 |
| 22mm tee (10) | £47 | £4.70 |
Worked example. A bathroom first fix with 10 elbows, 10 couplings and 10 tees in 15mm uses one bag of each: £18 + £14 + £29 = £61 for 30 fittings, or about £2.03 per fitting. Each fitting has 2 or 3 ends, so that is 70 pressed joints. If pressing saves you even one minute per joint over cleaning, fluxing, heating and wiping a solder joint, that is over an hour back on one bathroom.
The bigger cost is the tool. The MaxHeatUFH Electric Hydraulic Press Tool Set (MH-EHCS) is £899 inc VAT, October 2026, with 2 batteries and a charger. M-profile jaws are £79 each in 15, 22 and 28mm, so the tool plus those three jaws is £1136. Jaws for 35, 42 and 54mm fit the High Power tool (MH-HPEHCS) only.
Are press fittings as reliable as soldered joints?
Yes, when you use the right profile, the right jaw and a clean, square, fully inserted tube. A press joint is made by the tool, not by the skill of the hand on the torch, so results are the same every time. Most failures come from four mistakes, all of them avoidable:
- Wrong jaw profile. M-press fittings must be pressed with M-profile jaws. A U-profile jaw is for multilayer (MLCP) fittings and will not make a sound joint on M-press copper.
- Tube not fully inserted. Mark the insertion depth on the tube before you push it in, and check the mark sits at the fitting mouth before you press.
- Burrs or a ragged cut. A sharp burr can cut or roll the O-ring. Cut square and deburr inside and out.
- Missed joint. On a run of 50 joints it is easy to miss one. Press each joint as you go, and pressure test before you cover anything.
Soldered joints are just as durable when made well, but quality depends on cleaning, flux, heat and solder. Water Regs UK warns that flux residue left in the pipe is corrosive, so the pipework must be flushed after soldering.
How do you make a copper press joint?
A press joint takes about a minute from cut to finished, most of it preparation. Follow the fitting maker's instructions; this is the usual sequence.
- Cut the tube square with a pipe cutter. Don't use a hacksaw unless you clean up the end fully.
- Deburr the inside and outside of the tube end.
- Check the O-ring is in place, clean and undamaged.
- Mark the insertion depth on the tube with a pen.
- Push the tube into the fitting with a slight twist until it reaches the stop and the mark sits at the mouth.
- Fit the correct size M-profile jaw. Place it square over the fitting bead.
- Press until the tool completes its cycle. Don't stop partway.
- Check the joint, then pressure test the whole run before you box in, screed or fill the system.
When should you not use compression fittings?
Don't use compression fittings anywhere a joint will be buried or hard to reach on a water supply. Schedule 2 of the Water Supply (Water Fittings) Regulations 1999 says no water fitting may be embedded in a wall or solid floor, and that a fitting which consists of a joint designed to be operated or maintained must not be a concealed fitting. Compression joints can need tightening over time, which is why they are best kept to places you can reach, such as under a sink, at a tap tail or on an isolating valve.
Compression is still useful. It is the quickest way to make a repair with nothing but two spanners, and joints can be undone. Use a new olive each time you remake the joint, and don't overtighten: crushing the olive too far can distort the tube and cause a weep.
Do you need lead-free solder for copper pipe?
Yes, on any pipe carrying drinking or wholesome water, including domestic hot and cold supplies. Water Regs UK explains that the Water Fittings Regulations prohibit lead-based solder in these systems, and the water supplier can make the installer remove illegal lead-solder joints at their own cost. Lead solder is still allowed on closed central heating circuits, but most installers carry lead-free solder only so there is no mix-up on site.
Use a flux suited to lead-free solder, apply it to the tube only, and flush the system as soon as you can. Old fluxes made for lead solder can char at lead-free soldering temperatures and leave carbon deposits that speed up corrosion.
Can you use copper press fittings on gas?
Only if the fitting is made and marked for gas, and only if you are a Gas Safe registered engineer. Gas press fittings are a separate range with gas-rated seals, usually identified by yellow markings. The HSE states that anyone employed to work on gas appliances in domestic premises must be Gas Safe registered. The MaxHeatUFH copper M-press range is sold for heating and hot and cold water. Contact sales@maxheatufh.com before using any fitting on a gas installation.
Products for this job
- Copper M-Press Fittings: couplings, elbows, tees, reducers and valves, 15 to 54mm
- Copper M-Press Equal Straight Coupling
- Copper M-Press Equal Elbow
- Copper M-Press Equal Tee
- MaxHeatUFH Electric Hydraulic Press Tool Set (M & U Profile)
- MaxHeatUFH M-Profile Press Jaws
- Copper M-Press Lever Ball Valve
- Full Bore Lever Ball Valve, Compression, WRAS Approved
Related guides: M-profile vs U-profile press jaws explained, MLCP multilayer pipe for plumbing and heating and Connecting a UFH manifold.
Pressing the pipework for underfloor heating? Design the floor free with MaxHeatUFH ProLoop. Add your rooms and floor type, and get a loop design and full kit list with prices, from pipe and manifold to the fittings that connect it. Start your design
Frequently asked questions
Is it worth buying a press tool for domestic work?
If you make copper joints most weeks, usually yes. The tool and three jaws cost £1136 inc VAT at MaxHeatUFH (October 2026), and the time saved on each joint adds up quickly on first fix work. If you only make a few joints a year, solder or compression is cheaper.
Can I press copper fittings with a U-profile jaw?
No. Copper M-press fittings need an M-profile jaw. U-profile jaws are for multilayer (MLCP) press fittings. The MaxHeatUFH MH-EHCS tool takes both, so you can press copper and MLCP with one tool by changing the jaw.
Can you press a fitting onto wet pipe?
Yes. Unlike soldering, a press joint does not need the pipe to be dry inside, so it is useful when you can't fully drain a system. The tube end must still be clean, square and deburred.
Can compression fittings go under floorboards?
On a water supply, a joint designed to be maintained must not be a concealed fitting, and no fitting may be embedded in a solid floor. If a joint must sit under a floor, use a press or soldered joint and keep a pressure test record.
Can I reuse a compression fitting?
You can reuse the body and nut, but fit a new olive. An old olive has already been crushed to the shape of the previous tube and may not seal again.
Can I mix press, solder and compression on one system?
Yes. Many systems use press for the main runs and compression at valves and appliance tails. Just keep each joint type within its own rules, such as lead-free solder on water and accessible compression joints.
Do press fittings need a hot work permit?
No flame is used, so press fitting is not hot work. That is one reason press is preferred in occupied homes, timber-framed buildings and on sites where a permit is needed before using a torch.
Sources: Water Supply (Water Fittings) Regulations 1999, Schedule 2, Water Regs UK: solders and fluxes, BSI: BS EN 1254-7, BSI: BS EN 1254-1, BSI: BS EN 1254-2, BSI: BS EN 1057, HSE: gas safety FAQs