Junkers ZW20 boiler heat exchanger block. Reference: 87054062030
OBSOLETE PART. YOU CAN INSTALL THE FOLLOWING MODIFICATION:
ZW20 Heat Block
What is a boiler heat exchanger?
A heat exchanger in your boiler works by converting energy (heat in this case) from gas to water.
Water passes through the heat exchanger in the boiler, heating up in the process. The water is fed into the central heating system through a flow pipe. It circulates around the heating system and returns through the return pipe.
As water passes through radiators, towel rails, and pipes, it loses temperature. And when it re-enters the heat exchanger, it is reheated, and the process continues.
Possible faults of the Junkers ZW20 boiler heat exchanger
If it makes noise
Sign of limescale, sludge, or dirt buildup in the heat exchanger. That noise comes from the bubbles of heated water vapor
If the boiler turns off
If the boiler has an NTC probe, this probe monitors the temperature of the water leaving the boiler. If the temperature is too high, it will shut down.
When a heat exchanger is clogged with limescale or sludge, the water can overheat.
The probe recognizes that the water temperature is abnormally high and turns off the boiler.
Please note that in this case the Junkers , not the heat exchanger.
Water leaks
Accumulations of limescale, dirt, or rust can cause cracks in a heat exchanger.
This can cause leaks in the heat exchanger, which would then cause the boiler to leak water.
The internal components of the heat exchanger may also break or crack, and the boiler may not heat the domestic hot water or reach the correct temperature as well as in the heating system.
Solution:
If the problem is dirt, you can clean it with a descaler and reassemble it. If the heat exchanger has rust that won't come off or cracks, it must be replaced. Sometimes, simply cleaning it won't get it to reach the correct temperature. We always recommend replacement.
In any case, we have a specific spray for cleaning heat exchangers:
ACCESSORIES
COMPATIBLE MODELS:
SERIES:
7132318250
7713244870
7713230070
7713230065
7713243070
7713243067
7713230856
7713230857
7713243863
7713243864
7713231838
7713244867
7713230080
7713230079
7713243072
7713243071
7713230860
7713230868
7713243868
7713243869
7713230067
7713243068
7713231829
7713244864
7713230082
7713243074
7713230858
7713243865
MODEL:
ZW20AME23S2805
ZW20AME31S2805
ZW20KD23S2805
ZW20KD23S2895
ZW20KD31S2805
ZW20KD31S2895
ZW20KE23S2805
ZW20KE23S2895
ZW20KE31S2805
ZW20KE31S2895
ZW20-1AME23S2805
ZW20-1AME31S2805
ZW20-1KD23S2805
ZW20-1KD23S2895
ZW20-1KD31S2805
ZW20-1KD31S2895
ZW20-1KE23S2895
ZW20-1KE31S2805
ZW20-1KE31S2895
ZW20KD23S3595
ZW20KD31S3595
ZW20-1AME23S3505
ZW20-1AME31S3505
ZW20-1KD23S3595
ZW20-1KD31S3595
ZW20-1KE23S3595
ZW20-1KE31S3595







Manuel Ricardo López Pérez –
I replaced the old block after diagnosing internal corrosion. Now it heats evenly across the entire surface, and the hot water comes out uniformly.
Javier Alberto Morales Vega –
After installing this heat block on my Junkers ZWE 24, the thermal efficiency improved noticeably