single handle, shower, no hot

[mandc421]

10 year old single handle, twist only, in a small basement shower. i removed the cartridge and cold water shot out, plenty of pressure. zero hot water is coming out. this started probably with in the last 6 months. unknown make and model. no visible sign of mineral build up, no leaking. i'm thinking the balancing valve has failed and whole unit needs to be replaced.

your opinion please.

 

[hj]

You could have something like a Delta Scald Guard with a separate balancer. If so, there will be a "nut" on the body, usually to the right of the handle, to replace it. You do not replace the valve when a balancing spool gets stuck.