BPHE clogging

THE PROBLEM: In time in the hydraulic circuits it can pileup rust, chalk or other impurities. Rust gathers when you empty the hydraulic circuit and chalk gathers if the water is not softened.

These can end up clogging your BPHE. This means that your heat exchanger will suffer a decrease in efficiency or it will even break, in which case the cost of replacement can be very high.

This is our second installment in our “Watch out” series. Throughout this series of articles we’ll try to help you avoid mistakes and dishonest sales tactics when choosing your heat exchanger.

You can read here the other installments.

Why is clogging a problem

Because it always leads to expenses. For example, in the case of a chiller, if the heat exchanger breaks, then the cost of repairing it is very high – it can end up costing as much as a new chiller.

Protective solutions

Y filter

There are some standard protective solutions against rust or other impurities, one of them being the Y filter.

We discovered however in time that the sieve inside the Y filter rusts and ends up enlarging its openings. This leads to rust particles or other impurities passing through the sieve and entering the BPHE.

For this reason, we no longer use Y filters as a protection against impurities.


The standard solution against chalk gathering is washing the heat exchanger when you detect that it clogged.

However, it’s best you do this as few times as possible because:

  • The cleaning solutions are very acid and you risk breaking the older plates which wear down through time;
  • The washing procedure is a thorough one and must be done correctly;
  • With each washing cycle the risk of breaking the heat exchanger increases.

After washing the heat exchanger with a cleaning solution we recommend that you always circulate it and add a neutralizer solution.

The impurities separator

We believe that the best possible protective and preemptive solution against rust and other impurities is installing an impurities separator (or impurities electromagnetic separator).

We found this device to be much more effective at disposing of impurities than the Y filter. And we are using it for almost all our projects – it’s safer to use this device instead of the Y filter or instead of doing numerous washing procedures.

Let’s take for example chiller applications – for plate evaporators you must install the best possible protection against clogging to avoid breaking the evaporator. Its risk of breaking is higher than it is for other chiller components and the costs for its replacement and repair are also higher.

We believe Caleffi to offer the best impurities separators as we have tested their efficiency and reliability.

You can find them at almost any Caleffi distributor and we can also supply them. For small separators it might be better for you to buy them from a local seller, but for larger ones we are positive that we can offer you a very good price.

So, don’t hesitate to ask us for a quotation.

Key Takeaways

  • A clogged heat exchanger always leads to expenses
  • It’s best that you clean a heat exchanger as few times as possible
  • The impurities electromagnetic separator might be the best possible protective and preemptive solution against rust and other impurities

Read all our other
“Watch out” articles