Experiencing Water Leak from Ariston Gas Boiler's Safety Valve After Replacing It

Hello
I have a problem with the Ariston gas boiler. Water flows on the safety valve as it heats the water. I replaced the valve with a new 3/4 and the same. The thermostat is set to 1. If I give more, the valve is pouring. the water was drained from the flooded boiler. I don't know what could be the reason.

zbyniu84 wrote:

Water flows on the safety valve as it heats the water

There is a pressure increase when heating, so this is normal. A little water should flow until the pressure drops and the armature should close.

zbyniu84 wrote:

I replaced the valve with a new 3/4 and the same.

And what is your water pressure at home and what pressure is the new valve on?

A lot of water is dripping, so probably not normal. it seems to me that the problem arose after installing the check valve behind the water meter. I live at the end of the network, so the pressure may be low and certainly not constant, I can't measure it. is it possible that mounting a check valve caused this situation ???

It is not normal if water leaks from such a valve. It is not used for this (draining the water). Replacement valve (irreparable). What is a 3/4 valve (thread)? The pressure at the valve is important at the factory setting. Item Arthur

arturdip wrote:

Replacement valve

Do not read:

zbyniu84 wrote:

it seems to me that the problem arose after installing the check valve behind the water meter

And that's the truth.

zbyniu84 wrote:

is it possible that mounting a check valve caused this situation ???

Yes. Diaphragm expansion vessel to be fitted. When there was no check valve, the water flowed back into the network, and now there is no and the pressure in the system increases until the safety valve opens.

zbyniu84 wrote:

A lot of water is dripping, so probably not normal

This is very normal. The pressure builds up when the water is heating up and the pressure has to discharge somewhere. In the past it was not installed because there were no diaphragm expansion vessels and then the safety valve released excess pressure. There are currently such devices, so you can put them on, even it would be advisable. If for some reason this is not possible temporarily, it remains to drain the water from the safety valve, into a vessel, or install a hose that drains the water into the sewage system.
And when you buy a safety valve, you need to know what pressure is inside the building to buy the correct safety valve. If you buy a safety valve that is too big (pressure), the water will not drip, but an increase in pressure may damage the boiler tank.

stanislaw1954 wrote:

And when you buy a safety valve, you need to know what pressure is inside the building to buy the correct safety valve.

Buddy, safety valves are not selected for the pressure in the installation, because it may be incorrect, but for devices that are connected to this installation, unless the installation itself is designed for lower pressures than devices connected to it. Usually pipes withstand higher pressure than e.g. boilers. Sometimes in rural water supply there is high pressure, e.g. 8bar as it is for me and I have to use a pressure reducer to lower it to e.g. recommended for a washing machine. The boiler would not withstand such pressure, while the pipes can easily withstand 10 Bar. Of course, to protect the boiler, I also have a safety valve and a check valve at the inlet so that the water from the boiler does not go back to the drinking water, as well as in the DHW installation, a diaphragm expansion tank.