Solar pipe work banging !!!

[plumbbobshan]

Morning Lads
I have been called back to a job of banging pipe work. Its a solar drain back system with RESOL ER3 controls.(very basic) The 1st time i went to this job it was gerggling and low on water , i have changed the water for Glycol and all fine for about 2 weeks . Now the Cust has said the pipes are banging ! . Told them to turn it off. I would say the system is about 6 years old .

I am now thinking it could be over heating because the panel sensor is broken ?

It has a leak and needs topping up again ?

Any thoughts Lads :redface:.

 

[markfxy]

check the pumps ok drainbacks need a decent pump to push the air out of the system which could be causing overheating and banging, you dont need glycol in a drainback system they perform better without

 

[kimbo]

I have had this on a conventional solar system and it was the check valve, they go for a pastime. I dont know anything about the drain back systems but worth mentioning.

 

[wiggers1]

This is a common problem with drain back systems. Its most common cause is hot air expanding in the dry pipes above the collector. There is little you can do and this is why drain back systems are not widely used any more.