FAQ - Frequently asked questions

You will find a collection of frequently asked questions by the customers and the corresponding answers here. Our team will be pleased to advice you on questions of any kind. Please contact us via e-mail or telephone.

Is a pipe contact sensor needed for the separation system TE 1?

This question can not be answered with “yes” or “no” in general terms. If the separation system is used for separating the system of a heating circuit where the admissible flow temperature has to be securely limited, such as radiant floor heating, a pipe contact sensor must be installed as safety temperature monitor.

Does PAW pay the replacement costs of defective products?

You will find information on this topic in the manufacturer’s warranty

For what temperatures are flow meters designed for?

Maximum operating temperature in the flow: 120 °C Maximum operating temperature in the return: 110 °C

Where do I find a spare parts list?

You will find the item numbers of the spare parts for PAW valves and fittings in the installation and operation instructions, in the chapter “Spare parts” or “Scope of delivery”

Within which regions are PAW deliveries free of charge?

PAW deliveries are free of charge within Germany and from a value of goods of 750 €. For deliveries within the European Union, the delivery conditions are determined individually.

Is the material of the modular distribution manifolds, i.e. brass, suited for swimming pool technology, i.e. is it chlorine resistant?

No, the distribution manifold is not suited for the use in drinking water and swimming pool technology.

Can the heating circuit K33 be converted into a heating circuit K34 or K32?

Yes, PAW offers conversion kits for the conversion. The version and the type of the mixing valve you want to convert are decisive for choosing the correct conversion kit. We will be pleased to give you personal advice on this topic.

Can the PAW distribution manifold also be mounted reversely (upside down)?

Yes, this is possible without difficulty. Such an installation is especially recommended for piping coming from the bottom end. From the top face, the boiler connection has to be established or a separate (or several) heating circuit(s) can be installed by means of the coupling piece for overhead installation.

Can the flow of a PAW heating circuit with mixing valve be converted from the left to the right?

PAW offers the appropriate conversion kits for the conversion of the flow from the left to the right and vice versa. A non-use of these conversion kits can result in malfunctions of the mixing valve.

  • Conversion kit K33 to flow on the left: Item number: 340722.
  • Conversion kit K33 to flow on the right: Item number: 340711.

Can the end covers for modular distribution manifold systems be reordered?

Plastic end cap (installation from 01/2017)

DN 25: flow = item no. 34371V; return = item no. 34371R
DN 32: flow = item no. 37371V; return = item no. 37371R

Brass end cap (installation until 12/2016)

DN 20: flow and return = item no. 3137
DN 25: flow = item no. 3437V; return = item no. 3437R
No longer available! - DN 32: flow = item no. 3737V; return = item no. 3737R

Can PAW heating circuits be used for refrigerating or air conditioning systems?

The sealing material used as well as numerous pumps do not allow an operation in combination with cooling brines. Furthermore, please note that the insulation shell of the valves and fittings is not steam diffusion resistant during operation in cooling circuits, such as cooling ceilings and component activation with minimum temperatures of 10 °C. Therefore, a closed insulation must be completely sealed on site.

Can PAW armored hoses or corrugated stainless steel hoses also be used for gas, water or nitrogen applications?

No, the hoses are not suited for such a use.

Can the heating circuits be drained individually or do they have a filling or flushing device?

Yes, this is possible without difficulty thanks to the flush and drain sets. They consist of a self-sealing T-piece with a fill and drain valve. This unit is available for modular systems in DN 20-3/4″ and DN 25-1″.

Can immersion sleeves be installed in the heating group, in order to measure the temperatures for heat quantity measurement?

The immersion sleeve of the product range with 30 mm is suited for this. This immersion sleeve is generally installed in the flow ball valve. However, only one immersion sleeve can be installed per heating circuit because otherwise, the space within the heating group would not be sufficient. The second point for temperature measurement is generally integrated on the return side of the heat flowmeter.

Does PAW also deliver heat flowmeters for the heating groups?

No. Due to the large number of providers of heat flowmeters, we offer fittings for the return for the most prevalent types, in order to guarantee maximum flexibility. The most prevalent types are listed in our current catalogue. Thereby, the installation length for 3/4″ connection is of 110 mm and the one for 1″ connection is of 130 mm. There are two different versions. The first version is for the unmixed heating circuit, whereas the second version is for the mixed heating circuit. It is intended to position the build-in temperature sensor laterally in the flow of the PAW group next to the thermometer handle. Regarding the immersion sleeve, we recommend the version with an immersion depth of 30 mm from our current catalogue.

Does PAW also carry out commissionings?

On request, PAW also carries out commissionings.

Are stainless-steel corrugated hoses suited for potable water?

No, because they are not drinking water certified.

Are the stainless steel corrugated hoses oxygen permeable?

The Flexan hoses and the stainless-steel corrugated hoses are oxygen diffusion resistant.

Does PAW require a minimum purchase quantity or a minimum quantity surcharge?

No.

When is a mixing valve open and when is it closed?

To answer this question, a distinction between versions with flow on the left and versions with flow on the right must be made. For versions with flow on the right: In case of a pointer position of 9:00 o’clock (scale=0), only return water is added to the flow. In case of a pointer position of 12:00 o’clock (scale=10), only water from the boiler flow is added to the flow. For versions with flow on the left: In case of a pointer position of 11:00 o’clock (scale=0), only return water is added to the flow. In case of a pointer position of 7:00 o’clock (scale=10), only water from the boiler flow is added to the flow. Please note that the direction of operation of the actuators has to be changed when converting the flow.

Which heating circuit size goes with which distribution manifold size?

  • DN 20 heating circuit: DN 20, DN 25, DN 32, DN 40 distribution manifold
  • DN 20 distribution manifold: DN 20 heating circuit
  • DN 25 heating circuit: DN 25, DN 32, DN 40 distribution manifold
  • DN 25 distribution manifold: DN 20, DN 25, DN 32 heating circuit
  • DN 32 heating circuit: DN 25, DN 32, DN 40 distribution manifold
  • DN 32 distribution manifold: DN 20, DN 25, DN 32 heating circuit
  • DN 40 heating circuit: DN 40 distribution manifold
  • DN 40 distribution manifold: DN 20, DN 25, DN 32, DN 40 heating circuit

You will only need the transitions (not necessary within the same dimension).

Up to which temperatures do the gaskets of the heating circuits resist?

The gaskets are designed for the use in hot water heating systems with a maximum temperature of 110 °C.

Which type of actuator of the product range fits optimally on the heating groups?

We recommend the actuator SR5 or SR10. Up to a torque of 5 Nm, the actuator SR 5 can generally be used without difficulty for DN 20, DN 25 and DN 32. As from DN 40, we recommend to use the actuator SR10.

Which Viessmann actuator goes with which PAW mixing valve?

The item number of the accessory kit for Viessmann actuators (Dekamatik and Vitotronic) with 3-point suspension to a PAW mixing valve is: 705610. This accessory kit is suited for all nominal diameters (DN 20 to DN 50). Please consider the width of the actuators during the installation on modular heating circuits in DN 20. It is not necessary to mount the accessory kit for the separation system TE3.

Does the flow rate change if the bypass of the mixing valve is completely opened?

By opening the bypass, the flow rate in the secondary circuit is increased because the pressure loss via the bypass is lower than via the boiler circuit.The maximum flow temperature is reduced, because the amount of cold return water is increased. The mixing valve types K33 and K34 are suited for the realisation of a double mixing function, as it is used for systems with flow temperatures considerably below the temperature of the heat generator. Thanks to this mixing function and its correct setting, the controller characteristics of the heating circuit are significantly improved.

How must the mixing valve of a K32 be converted into a K33 in DN 25?

PAW offers conversion kits to convert different types of mixing valves. The version and the type of the mixing valve you want to convert are decisive for choosing the correct conversion kit. We will be pleased to give you personal advice on this topic.

How do I recognise if a check valve is activated or not?

During the operation of the heating system, the stamping on the regulating bolt must point at “Z” (Z = closed) for the heating system to be closed or activated. For filling, draining and venting the heating system, the stamping must point at A (A = open) for the check valve to be open or not activated.

How high is the temperature resistance of PAW valves and fittings?

Maximum operating temperature of heating installations: 110 °C Maximum operating temperature of domestic hot water modules: 95 °C Maximum operating temperature of solar transfer stations: 120 °C (primary), 95 °C (secondary) Maximum operating temperature of solar stations: 120 ° C

How can I convert a K33 controlled circuit with constant value into a K34?

PAW offers conversion kits to convert different types of mixing valves. The version and the type of the mixing valve you want to convert are decisive for choosing the correct conversion kit. We will be pleased to give you personal advice on this topic.

How can a modular distribution manifold be depressurised subsequently?

A solution is offered by the conversion kit for modular distribution manifolds in DN 20, DN 25, DN 32 and DN 40. Mount this kit on the left and on the right of the distribution manifold by removing the covers beforehand and by putting both distance rings in between afterwards. The distribution manifold is then depressurised and a pump can be operated in front of the distribution manifold. In case of installations with a high flow, it is recommended to install an individual distribution manifold module with hydraulic separator in front of the distribution manifold (DN 20 item number 3142, DN 25 item number 3442, DN 32 item number 3742). This module is mounted directly below the distribution manifold already in place (DN 20, DN 25 and DN 32). For DN 40, the module must be mounted in front of the distribution manifold The flow and return temperatures can then be measured more accurately in the distribution manifold, as the mixing of the flow and return has alreday taken place in the hydraulic separator. Please consider the pressure loss diagram of the catalogue for the dimensioning.

You can find part two of our FAQ here