Hello to you all,
I am getting water hammer in my radiators but it happens when the boiler turns on. Doesn't water hammer normally occur when you close a valve? I am sure that the noise is connected with the boiler because it happens at night when the only thing going on is the boiler turning on for the heating. By the way its a Vaillant instant water heater (i.e there is no hot water storage tank - it heats the water on demand). Could it be that the water pressure is too high? Any ideas would be great -it keeps waking our new baby!!
COMMUNITY FORUM
1-You have zone valves and one may be closing to fast.
2- The circulator may be over sized (wrong RPM)
3- You may have non electric zone valves and they might be "hunting" and this causes hydraulic also
4- The piping in cold ambient areas being hit with hot water can cause coefficient of expansion sounds.
5- Possibly the expansion tank may be flooded or if it is a diaphragm type the air has to be replenished.
6- There may be no compensation to allow slower acting solenoid valves closing.
7- Excessive velocity as the diameter of the piping is not sufficient for the GPM (FPS)
Sight unseen there are so many possibilities
2- The circulator may be over sized (wrong RPM)
3- You may have non electric zone valves and they might be "hunting" and this causes hydraulic also
4- The piping in cold ambient areas being hit with hot water can cause coefficient of expansion sounds.
5- Possibly the expansion tank may be flooded or if it is a diaphragm type the air has to be replenished.
6- There may be no compensation to allow slower acting solenoid valves closing.
7- Excessive velocity as the diameter of the piping is not sufficient for the GPM (FPS)
Sight unseen there are so many possibilities
I forgot to mention that it has only started in the last few months and seems to be getting worse. Does this narrow the possibilities?
I'll have a look. The boiler is only 5 years old. Should sediment be a problem? What about sediment would casue the hammer noise? I also found out that the expansion tank is built into the boiler. From this and your comment it seems that this is a boiler problem rather than a plumbing (e.g. radiator, water pressure, pipework) problem. I have a service contract with the boiler company so at this point I think I'll get them to look at it. Many thanks for helping me narrow it down (I hope). The last thing I wanted (or could afford!) was to have endless people coming around just pointing to another part of the system.
What do you mean the expansion tank is built into the floor?
How does one service it?
I think you need to have the service guy go over the system with you like explainging the auto feed and how to check your attitude and temperature and pressure gauges
Sediment on the bottom of a boiler (especially steam) robs the system from getting the max amont of heat.
The valve is called a blow down where someone removes about a gallon or less of water to make sure your boiler is clean internaly just like a hot water heater has that valve located on the bottom
How does one service it?
I think you need to have the service guy go over the system with you like explainging the auto feed and how to check your attitude and temperature and pressure gauges
Sediment on the bottom of a boiler (especially steam) robs the system from getting the max amont of heat.
The valve is called a blow down where someone removes about a gallon or less of water to make sure your boiler is clean internaly just like a hot water heater has that valve located on the bottom















