Client called us out due to them getting intermittent hot water throughout the home. Home is almost 3 yrs old, and client has a Rinnai tankless in the attic, which has a built in recirculating pump. The cause of this issue today was due to the check valve on the recirculating line getting hung up, and allowing cold water back in to the hot side. This is usually due to calcification build up from the constant hot water movement. I replaced the faulty swing check valve with a new 3/4” SPRING check valve, In an attempt to get client a little more life than that swing check lasted. Turned water back on to unit and turned recirculation back on and tested. Unit is now working as it should be. Client has not had their unit flushed since they bought the home brand new almost 3 yrs ago. Rinnai recommends servicing/flushing the unit every 2 yrs to help keep up maintenance inside the unit. 1 yr warranty on the check valve replacement.
