How to properly adjust and install the pressure reducer in your camper – this is how you avoid a dripping safety valve.

Are pressure reducers preset?

A pressure reducer might be labeled something like “1–3 bar.” This often leads to 
the misconception that it is preset. However, that’s not the case.

To ensure safe pressure in the system, the pressure reducer must be adjusted 
after installation while water is flowing. That brings us straight to the most 
common problem.

Adjusting the pressure reducer – Here's how

It often happens that people turn the adjuster on the pressure reducer and expect 
something to happen immediately. But the operating principle of this component 
works differently.

The crucial point is:

Here's how to proceed – step by step

1. Open a faucet so that water is flowing.
2. Use a screwdriver or Allen key and adjust the water pressure by turning 
   the screw on top of the pressure reducer while the water is running—turn 
   left for less pressure, right for more.
3. Close the faucet.
4. Now read the water pressure on a gauge (manometer).
5. If necessary, repeat until the desired value is reached.

The pressure will therefore be

• changed while water is flowing, but...

• read when the system is closed.

What problems can occur if the pressure reducer is incorrectly adjusted?

A correctly adjusted pressure reducer protects the peripheral components of the 
entire system. Many components aren’t designed for high pressures and can be 
damaged, which can lead to leaks and water damage in the camper.

The safety valve is constantly dripping.

To prevent problems from excessive water pressure, a hot-water boiler has a 
safety valve that is usually rated for a maximum of 3 bar. If this pressure is 
exceeded, the valve opens and water is released from the boiler to reduce 
pressure.

However, because hot water expands, the pressure reducer must not be set to the 
permissible 3 bar. The inlet pressure must be lower so that the limit is still 
respected when the water is heated.

It’s recommended to initially set the pressure reducer to 1.5 bar. That way, the sum of inlet pressure and thermal expansion stays just below the 3-bar threshold.

If you like, you can also start at 1 bar, heat up the system, check everything for 
leaks, and then slowly work your way up—until just below the opening pressure of the safety valve.

Pressure reducer with or without a manometer?

There are different versions of pressure reducers—those with an integrated pressure gauge and those without.

With built-in pressure gauge

We recommend this option for any DIY converter and for anyone who isn’t a 
specialist or doesn’t have a professional shop doing the work.

You can read the system pressure directly and don’t need an additional device.

Another advantage is that you can easily check the water pressure while traveling.

Without a pressure gauge

In this case, an external pressure gauge has to be connected at a water outlet in 
the camper in order to adjust the pressure.

The procedure is exactly the same, but the external test device is usually much 
more expensive, less practical to use, and doesn’t allow for later checks. So even 
if you can borrow an external gauge from a tradesperson or acquaintance—later, 
when you’re traveling, you simply won’t have it with you.

Correct installation position of the pressure reducer

Just as important as the setting is the position of the pressure reducer in the 
system.

The pressure reducer always belongs after the pump. If water filters are used, it 
should also be installed after the filter.

Up to that point, the component order is:
Tank → pressure water pump → accumulator tank → drinking-water filter.

Further along in the water system, the line is split by a T-fitting—one line (the cold water line) goes directly to the faucet, and the other line feeds the boiler and 
becomes the hot-water line.

A crucial point for positioning the pressure reducer is that it must be installed 
BEFORE this split in the water line.

Why not directly in front of the boiler?

Because we need the same pressure everywhere in the system.
If the pressure reducer were installed after the branch—i.e., directly before the 
boiler—then the boiler inlet pressure would be reduced, but the rest of the cold water line would still be at full pump pressure (for example, 4.2 bar with a 
Tigerexped pump).

If you then open the faucet in a mixed setting (half hot, half cold), you not only get less water on the hot side.

In addition, the high cold-water pressure of 4.2 bar is pushed backward through 
the faucet into the hot-water line and therefore into the boiler—and it stays there 
because there’s a check valve at the boiler inlet (the cold-water side).

So despite the pressure reducer being set, the boiler ends up seeing around 4 bar
—the safety valve opens—and that’s why it drips.
Only if the pressure reducer is installed before the split to cold and hot water will 
the entire system pressure be reduced and all components protected evenly.

Conclusion

A correctly adjusted (i.e., adjusted under flow) and correctly positioned pressure 
reducer ensures consistent water pressure throughout the entire system.
Our recommendation: use a pressure reducer with a pressure gauge—so you can 
check the system at any time, even while traveling.