Heating and water supply system project

Project description

Designing the engineering systems of a private house is a task that demands precision. A mistake in the boiler piping or the manifold layout can lead to rework and extra costs. In this article we break down a typical heating and water supply project created in the 3D editor pipes.applicode.ru.

This scheme is a ready-made solution for a house with a gas boiler, an indirect water heater, radiators and underfloor heating. Let's go through each assembly in detail.

Pipe colour coding in the project

To make the scheme intuitive, the project uses colour marking:

• 🔴 Red/yellow — heating circuit (supply and return).
• 🔵 Blue — cold water supply (CW).
• 🟠 Orange — hot water supply (HW).

This visualisation lets you quickly assess the flow directions and avoid getting lost at the pipe crossings.

Heating circuit: gas boiler, underfloor heating and radiators

Heat sources and back-mixing protection

A wall-mounted single-circuit gas boiler is used as the primary heat source. An electric boiler serves as the backup.

To prevent coolant back-mixing in the supply lines of both boilers, check valves are installed. This ensures that, when one heat source is running, the flow does not circulate through the idle boiler.

Mixing unit for underfloor heating

Hot coolant from the boiler is carried through a 32 mm pipe to the first branch. Here a mixing unit based on a three-way valve with a thermostatic head is installed. Its task is to lower the supply temperature for the underfloor heating system to comfortable values. The underfloor circuit has its own circulation pump and a simple manifold (without a built-in mixing unit, so mixing happens at the external three-way valve).

Radiator distribution

After the mixing unit, the supply line switches to a 25 mm pipe and runs to the radiator manifold. Distribution to the radiators is done using a manifold (radial) scheme — a separate line to each appliance. This allows any radiator to be shut off without stopping the system and ensures even heating of all appliances.

Control, filtration and bypass

The return line follows the configuration of the supply (25–32 mm). A strainer (dirt trap) is installed in front of the gas boiler. Pressure gauges are mounted before and after the filter, allowing you to visually assess how clogged the filter is by the pressure drop. The supply and return are also equipped with thermometers to monitor the temperature.

An expansion tank is built into the heating circuit to compensate for thermal expansion of the coolant. The supply and return are additionally connected by a bypass with a shut-off valve and a check valve. This solution prevents the coolant from circulating through the boiler in a small loop when the radiators are closed (protecting the pump from overheating) and also prevents reversed circulation when the underfloor heating pump runs.

Cold water circuit: cold water and make-up

The cold water line is equipped with a strainer and a water meter. Water is distributed to the water outlets through a manifold, providing an individual supply to each consumer.

The cold water line is connected to the heating circuit to make up the system. An expansion tank is built into the cold water line, with a check valve installed in front of it. This is a standard solution: the tank compensates for the thermal expansion of water when it is heated in the boiler, and the check valve prevents water from flowing back from the boiler into the cold water main when the pressure rises.

Hot water circuit: indirect water heater

The source of hot water is an indirect water heater (IWH), installed wall-mounted. The IWH has a built-in heating element for backup heating (electric top-up).

Water in the IWH is heated by a dedicated circuit from the gas boiler (25 mm pipe, amber-yellow marking on the scheme). Hot water is distributed through a manifold, just like cold water. A thermometer is installed on the hot water line to monitor the temperature.

Both expansion tanks (cold water and heating) are equipped with shut-off valves (polypropylene) and drain valves (metal). The IWH is also equipped with a drain valve and a safety valve to protect against excess pressure.

Why is such a project convenient in 3D?

Flat drawings often do not give a full understanding of how the system will look in reality. In the TuboTools designer, this project can be:

• Rotated and viewed from any angle.
• Zoomed into complex assemblies (boiler piping, mixing unit).
• Used as a ready-made template for your own design.

This project is an excellent basis for anyone who wants to understand the scheme or show a client the future installation.