WattsHY-420 Repairinstructions pdf

I have this Watts HY 420 LF on the exterior of my house. When turned on it leaks from behind the nut for the adjustment key and also from the holes around the hose bib. Is this something that I can fix myself? Or do I need to call a plumber to replace the whole unit?

Cash Acme offers an extensive range of temperature and pressure relief valves, with models that are perfect for home, business or industrial applications.

wattshy-420lf parts diagram

Our products are ASME, ANSI and CSA (AGA) approved to protect water heaters from excess pressures and temperatures by discharging water. Thermostatic relief valves are completely automatic and reset after the pressure has been relieved.

Cash Acme is an industry leader in producing Temperature & Pressure (T&P) Relief Valves for water heaters or hot water storage tanks. In fact, we've been a trusted source of plumbing solutions for more than 100 years. Each pressure relief valve is tested for top plumbing performance, quality and efficiency before it leaves our factory.