Hi All. First time posting and looking forward to reading more on this valuable site.
Here is my current problem. This 5 story 5 family building with 5 bathrooms, 5 kitchen sinks and dishwashers needed to have a Gould Aquaboost II installed 7 years ago because the City water pressure was only 32 psi. This 1HP HMS pump (model 2HM1E2D) variable speed constant pressure pump is set to give me 50 PSI at the pump outlet.
We just changed our boiler out and have a new steam boiler with a power burner and a hot water coil. The attached drawing shows the domestic hot water board mixing panel. A circulator was installed as you can see in the pictures. It is a Bell and Gossett NBF-25 103418LF1M61. I can supply pump curves. The circulator pump has 3 speeds and it was left at speed two in the beginning. What we noticed was that for some reason, on some occasions ( which I am trying to pinpoint what is happening in the system when we see this) the pressure gauges around the mixing valve , p2, p4 and p5 ( but not p3...probablyt because of check valve. would go to 100psi on the gauges.... scary! since they looked pegged. When hot water was used the pressure would get immediately releaved and drop back down to 50 ish psi.
The guy who built the board came in and dropped the speed to 1 on the circulator. Now I see it goes to around 70 is PSI on those three gauges.
Can anyone see what in this system could be causing that?? Is the circulator the problem? Or how the system is piped? The guy who built the board would leave some of the valves cracked instead of open as you can see in the picture of the board.
I am very concerned that this may open up some joints in the hot water system running up to the apartments.... any suggestions or ideas are very much appreciated!
Thank you, Doug