Heating pumps and circulation pumps – high efficiency, collection in Hagen

Heating circulation pump, hot water circulation pump or heating circuit station: Which is for what?

The heating circulation pump moves heating water from the heat source to the radiators or underfloor heating and back. The hot water circulation pump keeps hot water moving through the drinking water pipe so it reaches the tap warm sooner. The heating circuit station comes with a pre-assembled pump, mixing valve and actuator for a mixed heating circuit. We offer WITA pumps for these applications:

WITA pumps: applications, specifications, connections

Pump	Application	Specifications	Connection
WITA Delta MIDI 40	Heating systems, new builds and refurbishment	Head 4.0 m, 2,800 l/h, 3 to 23 W, EEI ≤ 0.18	DN 15 to DN 32, installation length 110, 130 or 180 mm
WITA Delta MIDI 60	Heating systems in residential and commercial buildings	Head 6.0 m, 3,600 l/h, 3 to 42 W, EEI ≤ 0.20	DN 15 to DN 32, installation length 110, 130 or 180 mm
WITA HE + go.future	Heating systems, including modernisation	Depending on model, head of 4, 5 or 6 m, 23 to 41 W, EEI ≤ 0.20	DN 15 to DN 32, installation length 110, 130 or 180 mm
WITA go.future 2	Heating systems in single-family and multi-family homes	Head up to 6.0 m, up to 41 W, EEI ≤ 0.20	DN 25, installation length 180 mm
WITA go.future Z	Domestic hot water circulation	Head up to 1.4 m, up to 650 l/h, 2.5 to 7.0 W, fluid up to 65 °C	DN 15, installation length 81 mm, brass housing
WITA SM-W heating circuit station	Mixed heating circuit, for example for underfloor heating	Mixing valve with bypass, actuator, circulation pump, flow and return thermometers	DN 25 or DN 32, centres 125 mm, boiler flow on the right

Related components: Heating system components, Expansion vessels and Underfloor heating.

Replacing a heating pump: Which dimensions matter?

The new pump must fit the space left by the old one. Read from the rating plate or measure the connection size (DN), the installation length between sealing faces and the head. If the connection size and installation length match, the pipe components need no alterations. Delta MIDI 40 and 60 and HE + go.future are offered with DN 15 to DN 32 connections and installation lengths of 110, 130 or 180 mm; go.future 2 is DN 25 with 180 mm. We confirm available combinations in our reply.

The old pump's head is an initial guide; the installer determines the precise requirement during hydraulic balancing. Our heating pumps provide 4.0 m (Delta MIDI 40) or 6.0 m (Delta MIDI 60, go.future 2); HE + go.future is available in models with 4, 5 or 6 m head. We confirm which model we supply in our reply. If your heat source controls the pump via a PWM signal, Delta MIDI 40 and 60 are optionally available as PWM versions.

Setting a circulation pump: Curve and level

High-efficiency pumps adjust their speed to demand. The operating curve determines how:

• Proportional pressure: The pump reduces its head as thermostatic valves close. This is generally the first choice for radiators with thermostatic valves.
• Constant pressure: The head stays the same regardless of how many circuits are open. This often suits underfloor heating.
• Constant curve: The pump runs at a fixed speed, like a conventional stepped pump.

The go.future 2 has four constant and four proportional curves, indicates the selected one by LED and has a key lock. HE + go.future adjusts itself with SMART-Adapt and reduces its output automatically at night. The Delta-MIDI pumps are set using One-Touch, and both have a minimum operating mode. The basic rule: choose the lowest setting that keeps all rooms warm. Noise at thermostatic valves suggests the setting is too high.

Hot water circulation and mixed heating circuits

The go.future Z is built for domestic hot water circulation: brass housing, fluid temperature +5 to +65 °C, three constant curves selected by One-Touch and ceramic bearings. A heating pump cannot replace it.

When radiators and underfloor heating share a heat source, the underfloor heating usually needs its own circuit with a lower flow temperature. The WITA SM-W heating circuit station provides this: the mixing valve blends in return water, the actuator adjusts it according to the heating controller's signal and the built-in pump circulates the water. Check which side your boiler flow is on first, as the station is designed for flow on the right.

Installation: Electrical connection by a qualified electrician

• Before removal: Switch off the power and isolate the pump on both sides or drain the system.
• Installation: Observe the flow direction and fit new flat gaskets. Delta-MIDI pumps come with gaskets and a thermal insulation shell.
• Afterwards: Fill the system, vent it and check the pressure. The go.future 2 has a venting function for this.
• Electrics: The pumps operate on 230 V. A qualified electrician connects both the pump and the actuator.
• Drinking water: Work on the hot water circulation pipe must be carried out by a registered installer.

Sealants and tools are listed under Consumables and Tools; the KFE fill and drain valve for topping up under Ball valves.

Collection in Hagen or delivery

Our pumps are order items. You collect them from our Hagen warehouse after they arrive; we provide the date when replying to your enquiry.

1. Select the pump, including connection size and installation length for heating circulation pumps.
2. Add it to the enquiry list, with sealants if needed.
3. Send your enquiry, with a photo of the old pump's rating plate if you wish.
4. We reply by email or telephone with the price, availability and collection date.

Warehouse: Im Mühlenwert 22, 58135 Hagen. Shop: Eilper Straße 29, 58091 Hagen. Shipping on request. Further details: Collection and enquiries and Locations.