Ariston Velis 50L Boiler: Leaking Safety Valve During Heating - Causes and Solutions

Hello, I have a problem with the Ariston - Velis 50 L boiler, or rather with the safety valve that has been added to the boiler. The case is that I have recently renovated the bathroom with the replacement of the water system in the kitchen and bathroom (three-story block). Everything from the main pipe in the riser has been replaced with copper + a new counter. The problem will appear when the water is heated by the boiler, interestingly, dripping starts after 5-10 minutes of heating and lasts all the time. The only way to stop dripping is to turn on the water or flush the toilet. The guy who did the renovation is coming in a few days but I have the impression that he probably doesn't know what's going on. Is it just a matter of a broken safety valve or the cause could be more serious. Please help me and give me some suggestions on what to do now.

This is the expansion of water with temperature. A diaphragm vessel for pressure absorption should also be installed. If it is not there, the situation will get worse because the valve will become overgrown with scale.

The valve may be damaged or maybe it works on the limit of activation because you have high pressure in the water system by default.
Measuring the idle pressure will solve the mystery.

grzeskk wrote:

This is the expansion of water with temperature.

It's probably not because the water drips literally after 5 minutes from turning on, which is cold.

A.Gieronimo wrote:

Measuring the idle pressure will solve the mystery.

So in theory replacing the valve should help? If the pressure is too high, what can be done about it?

Buddy, it's your business, you can replace the valves if you think it will help. However, without additional space for expanded water, you will not eliminate the problem.

grzeskk wrote:

Buddy, it's your business, you can replace the valves if you think it will help. However, without additional space for expanded water, you will not eliminate the problem.

It depends on the construction of the water network, supposedly there is a requirement to install a non-return valve at the entrance to the building, but it depends when the installation is being built, if there is no non-return valve, the water should flow back into the installation, unless it is.

Even though there is no non-return valve at the entrance to the building, there is probably one in the safety valve. I wonder why they usually have an arrow with the direction of water flow on them?

The valve attached to the boiler usually allows the water to flow back and then there is no need to install an additional expansion vessel. I operate several boilers and the backflow of water through the factory-attached valve takes place without any problems. The old professions (from 10 years ago) did not have this possibility. It is different when a non-return valve or a water pressure reducer is installed at the entrance to the building (often found nowadays, it also has a non-return valve in itself) then there is no choice but to install an expansion vessel specially dedicated to hot water installations (usually beige in color, higher usable pressure ).

Today there was a specialist and he set up a pressure reducer behind the counter: http://allegro.pl/reduktor-ciscenia-wody-goshe-1-2-z-manometrem-i6666088101.html and unfortunately it did nothing. The pointer rises to 7 bar during the adjustment, you can see a significant drop in water pressure, e.g. in the tap, but the pointer still goes up to 7 bar, and at 6.5 it releases the safety valve. I don't know what to do next. Anyone got any ideas?

Adjust the reducer.

gersik wrote:

Adjust the reducer.

All in all, I've never had contact with such a reducer and I don't know how it works. I tightened it halfway (about 3 bar) and I don't see any difference.

You have read the manual. The reducer must first be released and then tightened to set the appropriate value.

gersik wrote:

You have read the manual. The reducer must first be released and then tightened to set the appropriate value.

Well, there are no instructions. In the box there was only a reducer and a pressure gauge.

Kurtka na wacia wrote:

Can you show a photo of how this reducer was mounted? And the professional who installed it could not adjust it?

In the picture it is a little less, I show it because the boiler has just finished heating and it has dropped a little from 7 bars. The expert probably did not know what and how. I don't know if it's normal that while the boiler is heating the needle on the pressure gauge slowly rises to 7 bar, and after turning off it drops down.

the reducer probably won't help unless you set it to 1.5 bar, but it's not enough to make the water comfortable (3 bar is probably the optimum), all you have to do is install an expansion vessel of about 10% of the boiler's capacity, or lower the heating temperature. Because you didn't write to what temperature do you heat the water?

jarcecz wrote:

Because you did not write to what temperature do you heat the water?

At first I heated it to 80 degrees, now I reduced it to 60 but I don't see any difference.

I do not know how many people use this boiler, but such a high temperature is not recommended, the optimum temperature is about 42 C. The rule is that the lower the temperature, the longer the heater lives, there is less scale and lower bills, heat (energy) losses in maintaining 60 or 80C are incommensurable with 42C. And the water should be at such a temperature that after turning it on, you do not need to adjust the cold. At a temperature of 60C, an expansion vessel with the same pre-pressure as on the reducer.

The boiler heated up to 60 degrees and the needle dropped to two bars. It seems that only when it heats up the pressure rises.

Kurtka na wacia wrote:

Have you heard of legionella bacteria? And 42°C is a failure in my opinion. The water in the boiler runs out quickly, the dishes are not washed

Once a month, increase the water temperature above 65°C to eliminate bacteria and guarantee water hygiene. (from the website http://www.ariston.com/pl/VELIS)

did the valve open to get these 2 bar?

blachunter wrote:

did the valve open to get these 2 bar?

It seems that as the water heats up, the pressure drops. The safety valve is open for almost the entire heating period when the pressure builds up.

I see you have gone off topic. Maybe someone can explain to me why the pressure in the system increases so much when heating water.

When water is heated, its volume increases as it has already been written here. The pressure reducer acts as a non-return valve and therefore the pressure builds up from the start of water heating. And to what pressure it will rise depends on the difference between the temperature, i.e. the initial and the set temperature, as well as the ratio of the boiler capacity to the capacity of the installation connected to it from the reducer. I saw the installation just after installing such a reducer with a 140l boiler and a fairly small water installation. After the heating started, the pressure on the pressure gauge grew in the eyes until the end there was no safety valve because the pressure was reduced by the hydrophore tank until the pressure reducer was installed. My advice, as some wrote, you need to install a diaphragm vessel and after the problem.

Please replace the safety valve with a valve with a higher pressure. After a few years, they can leak. Or it is stoned (also to be replaced) after arthur

Install the diaphragm vessel and the problem will be over.

The diaphragm vessel does not make sense as there is no check valve. item artur