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chico 54
hot water boiler noise

I have two problems. My system is a hot water boiler,3 years old[Buderus,Logano C124} with 3 zones contoled by ESP zone valves. Two of the zones are bsaeboard heat and one is cast iron radiators. Problem #1. When the zone valves close I get a very loud WHOOSHING noise. It seems to happen on any of the 3 valves but is more pronounced on the zone with the radiators.It was suggested by a contractor that I install a delay switch which would shut of the pump 10seconds before the valve closes ,therefore eliminating the water pushing against the valve as it closes. I can't see how this would help if more than one zone is calling for heat at the same time.
Problem # 2. More worrisome. During the night after the system has not run for some time,so the water in the radiators is cool, When the boiler turns on ,pump comes on also ,I get mild banging. The sound is like someone stricking the pipes with a small hammer. Any ideas?

Re: hot water boiler noise


This zone valve (Energy Storage Principal (ESP) is according to the Taco literature nearly identical & interchangeable with the Taco Electronic Ball Valve (EBV) in that it uses an internal capacitor instead of the usual spring to return the valve to its normal postion.

The valve's normal position is NORMALLY CLOSED---during which time the boiler is not running and the t-stat contacts are open and NOT calling for heat.

When the room's t-stat contacts close (call for heat) energy is applied to that room's zone valve in the cellar to open it (opening takes 90 seconds on most valves) before the boiler/burner can fire & circulate water thru that particular zone; an END SWITCH inside the ZV eventually makes contact with the T or TT (thermostat) terminals on the boiler to activate the aquastat relays & fire the burner & circulator to supply hot pumped water thru the zone.

This action is reflected by the little green diagonostic LED diode at the top of the valve that lights and flickers during the various stages of this opening and closing of the valve.

At the END OF THE CYCLE, the t-stat in the room opens when it is satisfied that there is enough heat in the room, removing energy from the end switch inside the zone valve & the plunger on the ZV starts to close--with older spring versions of this ZV the closing takes 90 seconds---so there is no banging---energy to the circulator/burner is cancelled & they both stop operating.

The site below describes the green diode LED action---it also describes an action of the ZV "finding it's home position" when it is first activated when the boiler is first installed---apparently the top half of the ZV (actuator) can be positioned in several positions (to avoid cramped spots in the boiler room) & still operate normally---in the event the actuator dies completely, it can be eaily removed without draining the system (after the power to the connecting wires has been shut off & the leads labeled & disconnected).

There is also a "manual overide" button at the top of the valve for the purpose of manually opening the ZV in the event of an internal failure of the valve (so that heat can be maintained in that zone).

Check the position of the top portion of the valve (actuator) to make sure it is in its proper position---it might be possible to try other positions for the actuator to see if that clears up the problem---after you check the wiring, etc.

Also consult the site below for the wiring diagram & check to make sure the wiring is correct on all the valves, also check wires going back to the little transformer & any junction box that may be present.

Make sure the blinking green LED diode is doing what it's supposed to during the various stages of opening & closing of the valve & the t-stat calling for heat, etc.

The fact that all 3 ZV's are acting up makes me suspect some kind of a wiring error or minor short---make sure no strands of the copper wire are touching any adjacent screw terminals or metal housing, etc. & that the wiring job jibes with the wiring diagram below.

It would be well worth a call to Taco's technical support help line at (401) 942-8000---sorry, I couldn't find an 800 number anywhere on their website---I'm sure they've run into this problem numerous times before.

Also Google phrases like "taco esp zone valve problem", "taco ebv troubleshooting", etc, (with & without the quotes).

Did this problem crop up recently, or has it been this way for some time, or since the system was installed???

At Taco, ask for Joe Mattello, Carl Perrone, Terry Sands, Mario Silva or George Taber.


chico 54
Re: hot water boiler noise

Thanks for the response.I'll follow up on all you suggest. The problem with the WHOOSHING sound has been there since the boiler was installed .It may have gotten a little noiser lately, But it could be I am overly focused on it. I'll check this out and post my results. I had already sent an e-mail to Taco. Thanks again.

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