To power flush both combi heat exchangers

[Philip123]

Some say do not power flush either of the combi heat exchangers in situ and some say it is OK.

I intend to put a pump adapter on a Bosch pump in a Worcester Combi 24CDi and first power flush the central heating system, including the central heating heat exchanger. Then isolate the flow and return for the central heating.

Then turn on the kitchen sink hot water tap which will cause the diverter to go through the domestic hot water heat exchanger and power flush. I will use the recommended chemical.

I will strictly take a PH and TDS reading of the water that comes out of the hot tap before I begin and then make sure it is safe after I finish power flushing.

My question is:-
Should I power flush The heat exchangers or am I likely to damage them.

[diamondgas]

Hi Philip123, Power flushing has its limitations be aware! I'd consider flushing the system and once thoroughly cleaned test it out. Replace the plate heat ex if the flush doesn't make the improvements I'm assuming you're after. The 24CDi didn't give the greatest of hot water supply new, bye-the-way!

[Philip123]

Thanx for the reply diamondgas.
So would you power flush both heat exchangers in situ, ie while both heat exchangers are in the combi boiler?

[diamondgas]

I'd need to know a bit more about the reason to powerflush. If it's to improve hot water supply I'd be inclined toward replacing the plate heatex rather than trying to clean it out. I'd also need to know that the diverter valve is closing fully on hot water demand, nothing going to radiators. I'd be checking the system water to see how bad it is in need of a flush and if necessary flush the heating system prior to replacing the plate heat ex. Powerflushing does not guarantee removing the build up on either heatexchanger what it does do is remove the suspended magnetite in the system water. Long time back at BG we developed a process for cleaning out Chaffateaux boilers with an aggressive chemical that did remove the linings on the heatexchangers. By isolating the heating system filling the boiler only and running it in hot water mode it circulated around the boiler only. I don't know if there's anything out there now that'll do the same job, maybe someone here can help you more along that line.

[AlexGas]

I use KAMCO FX2 POWER FLUSH CHEMICAL to clean plated heat exchanger.
Neat, soak it for a half an hour, rinse it out well, comes out like new.
Works for me.