Ariston Temperature and Pressure Valve Union 570199

This is an Ariston temperature and pressure valve union, supplied as product code 570199. It is a boiler component that combines temperature and pressure relief in one body, protecting the appliance circuit by opening when either limit is exceeded. The union carries male and female threaded connections at 3/4 inch and 1/2 inch, and is specified for appliances up to September 2008.

• Water weeping or discharging from the valve outlet when the system is at normal operating pressure
• Continued dripping after the system has cooled, indicating the valve is not reseating
• System pressure or temperature rising without the valve discharging
• Visible scale, corrosion or damage around the valve body or threaded connections
• Leaks at the union joints where the valve meets the appliance pipework

• Confirm the appliance model and build date, as this part is specified for units up to September 2008
• Check the existing connection sizes on the appliance, which are 3/4 inch and 1/2 inch on this valve
• Verify the Ariston part number 570199 against the marking on the component being replaced
• Check the system pressure and expansion vessel operation before condemning the valve