Junkers Novastar ZW20 1AME23 Domestic Plate Heat Exchanger Ref. 8705406203

Junkers boilers compatible with reference 8705406203

Plate heat exchanger with reference 8705406203. Ten verified compatibilities: ZW20-1AME23 and ZW20-1AME31.

Proven compatibility

Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.

How to check if ref. 8705406203 is the part for your boiler

What determines it is not the boiler model, but the reference printed on the part you already have installed.

1. Find the reference printed on the installed part and check whether it matches the catalogue reference 8705406203. If it is not visible, do not identify the part from its shape alone.
2. Check the full boiler model on its data plate and look for it in the model associations on this page.
3. Compare the connections and physical body with the original part before installation.
4. If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.

Symptoms and faults that the heat exchanger 8705406203 solves.

The plate heat exchanger transfers heat to the domestic hot water. These are the typical symptoms and what to do:

Common symptoms and faults

• 01

  Hot water comes out of the tap, but it loses temperature or cools down if you let the water run for a while.

  Cause: The plate heat exchanger is not transferring heat well because it is scaled with limescale.

  Before changing it, measure if the flow of hot water has also decreased: if little cold water comes out, it may be the dirty inlet filter, not the heat exchanger.

• 02

  The boiler works well for heating, but the domestic hot water never really gets hot.

  Cause: The plates of the heat exchanger are partially obstructed, which prevents good contact between the heating circuit and the domestic hot water.

  First, check the domestic hot water temperature set on the boiler and ensure that the burner ignites at maximum power in hot water mode.

• 03

  The heating circuit needs to be refilled with pressure more frequently than usual, without seeing any leaks outside the boiler.

  Cause: An internal micro-leak in the heat exchanger allows water to pass from one circuit to another without any visible exterior moisture.

  Check the expansion vessel and the bleed valves before suspecting the heat exchanger; they are the most common cause of pressure loss.

• 04

  The domestic hot water comes out with just the right pressure, but you notice a whistling sound when you turn on the tap.

  Cause: The narrowing of the heat exchanger channels due to scale reduces the water flow and generates turbulence.

  Measure the incoming water supply pressure before replacing the part; low pressure can cause the same symptom.

These symptoms can have more than one cause. If your boiler displays a fault code, send it to us via WhatsApp along with a photo of the labeling, and we'll tell you if this is the part.

Data sheet for Junkers plate heat exchanger 8705406203

Catalogue reference

8705406203

Brand

Junkers

Type of part

Plate heat exchanger

Units in stock

1 unit

Status

Refurbished

Warranty

1 year

Shipping

Delivery time shown at checkout

Return

14 days