No Hot Water in Boiler: Circulation, Copper Pipes, 20kW Furnace, 60°C Temperature & Hissing Sound

Hello!

A week ago there was a strange hot water situation. Well, after firing in the furnace (20kW) and circulating only the boiler, there is no hot water, as it used to be before. Before this failure, 45-60 minutes after firing up, the water in the boiler was ready for bathing. Now, for example: I smoked at 1 p.m., at 2 p.m. I went to the shower, after max 30 seconds only cool water started to flow. At 5 p.m. the water was only reasonably warm - but not very suitable for a shower. In an oven, it is heated to ~ 60 ° C. The copper pipes leading to and leaving the boiler (from the stove side) are hot - at the temperature of the pipes coming directly from the stove. The system has only one pump for the entire installation. Now in the bathroom you can hear a kind of hissing in the pipes that are in the wall, but after closing the water supply from the hydrophore (capacity about 500l) to the boiler, there is no hissing. After a long while I opened the hot water tap in the bathtub, the hissing also stopped - the question is for how long? The hydrophore pump is often turned on (water from a deep well, quite hard). As a precaution, we replaced the "dragon" in the well. Air was also pumped into the hydrophore. The hydrophore is still activated frequently, but not as often as at the beginning of the failure. After releasing water on the radiators, they are all hot and there is no air in them. I even released the flare nut on the return of water from the boiler to the stove, no air, the water flowed normally. The furnace with the boiler is located in the basement. All radiators are on the ground floor at one height, except for the second radiator in the bathroom, which is 1.8 m high. Additionally, the same heater is usually always warm, even if it is only used with water in the boiler. Tank for expansion vessel at a height of 2.3 m. Installation founded 5 years ago. The bathroom was renovated 3 years ago, then the water installation was changed - a bathtub and a shower. The boiler has a capacity of 120l - 2m away from the tap in the bathroom. As a curiosity I will add such a thing. Before the above-mentioned problem, hot water was used on Tuesday, 5 people had a bath, and in the morning on Wednesday the water was still slightly warm. Now, on the next day, the water in the boiler is at the temperature of the water in the hydrophore - that is, mega cold. Could there be a situation that the coil in the boiler air has air to air? The pump works like normal, switching to individual 3 gears can be heard and felt after touching it. I am not an expert in plumbing, so a little understanding please ;)

PS: hot water at the moment of writing this topic, but I don't know if the problem will go away.

If both pipes, supply and return, are hot, it means that there is a CO water circulation, not only heat exchange takes place. Is the boiler with a jacket or with a coil? The mantle could have deposited limescale in the form of silt, leaving only a small channel for the flow of water from the feed to the return, which would explain a hot return. First, I would try to rinse the heating circuit with water from the hydrophore.

hello, in my opinion, for five years there would not be enough limescale to clog the heating medium circuit. , then the water from the return will push the air up towards the unscrewed screwdriver. of course you do it buddy when the stove is not burning and the installation should be full.

@-RoMan- 18
Much depends on the hardness of the water and temperature, and the higher the temperature in the boiler, the more limescale deposits.
Therefore, in my opinion, in the case of very hard water from wells, this clogging after 5 years is possible and after this period it would be appropriate to perform a comprehensive inspection and possible cleaning.
In practice, a small layer of scale can significantly reduce the heat transfer efficiency, so inspections and cleaning should not be underestimated.

This hiss in the wall could be a leak. This would explain the long heating of the water, because the boiler still receives cold water despite the lack of consumption. I would look in this direction.