Hansgrohe Thermostatic Valve Pulsing

I just installed a Hansgrohe Thermobalance I in a new shower. Everything works fine when the temperature is set to either the hot or cold ends of the spectrum. The problem is when it is set some where in the middle ... you know ... where people actually like to shower. The water flow pulses pretty badly in this range. It seems to me that the valve is constantly trying to adjust the temperature and overshooting, almost like a drunk trying to keep his wheels between the dotted lines. Is this a common problem with thermostatic valves? Could it be a problem in the supply lines somewhere?

Thanks

Are you certain you don't have hot and cold reversed? That would cause that.

Pretty sure nothing's reversed. The valve has a tab to prevent it from being installed upside down. Also, when I turn it all the way to hot, hot comes out and all the way to cold makes cold come out.

Is it possible I just got a lemon? Hansgrohe is closed until Monday so it looks like I'm showering like this or it's going to be a stinky Christmas.

Its very possible to have lemons

Its also possible that some sediment in the valve could be creating your problem .

ie: a tiny ball of solder

Hmmm ... some sediment in there is very possible. Water was pretty brown on the initial run. I thought I had flushed out all of the bread I used to stop the water while I soldered, but you never know. What would be the best way clean out the valve?

The best place to start, take apart the check valves/stops (they should look like slotted screws stops). They are retained by packing nuts. There will be a hot and a cold. Most are spring loaded , so be careful it doesn't spring out at you (DO NOT LOSE ANY PARTS).
Then flush the water through the valve (hopefully clearing anything that might be in there. Then make sure the check valves/stops are clean of any debris.

Your cartridge has filter screens to catch dirt particles and protect the thermostatic element. If you used bread to make your tie in, the screens are probably clogged. The solution is as follows. Remove the trim plate and handle. If you have one of the ThermoBalance valve models, you need to hold the wrench flats steady (They are positioned at 9 and 3 o'clock) then remove the 94282000 cartridge by turning the large hex nut counter clockwise while holding the wrench flats at 9 & 3 o'clock. Once removed clean the filter screens. Before replacing, you should turn the barrel of the cartridge counter clockwise (water should be on) about 1/4 turn to clear any debri left in the valve. Reinstall the 94282000 cartridge into the unit and reinstall the trim. The handle will need to be recalibrated. You should find the instruction manual for the directions.

If you have the Ecostat or EcoMax valve, you must turn the water off at the service stops first. Then remove the center thermostatic cartridge and clean. Cycle the service stops to confirm strong flow and flush the valve before replacing the thermostatic cartridge.

Thermostatic valves are wonderful and can supply alot of mixed water for larger demand. Hansgrohe tests 100% each cartridge before it ships to you, so you should never get a lemon. Best shower product on the market in my opinion.

If you have the same problem after cleaning and flushing your valve, the other reason can be an undersized instant water heater. Thermostatic valves cannot cope well with differing pressure between hot and cold. Instant water heaters can reduce the pressure on the hot side too much for the valve if it is undersized.

Also, Hansgrohe has a knowledgeable technical service department. If you need more support, contact them at 800-334-0455 from 8:00 to 6:00 M-F

Best regards,

Europlumber

Thanks for the advice everyone. I cleaned the filter screens and the situation improved tremendously, but it still was not perfect. However, after a couple of showers, the problem has cleared up completely.

So, great advice, but I can't quite shake the feeling the EuroPlumber is employed by Hansgrohe.

You may be on to something. I have worked for several German plumbing suppliers and also owned a service plumbing business specializing in working on and installing european plumbing. I answer questions on Terry's site because I have the knowledge to give you good information.

I am currently the Technical services manager for Hansgrohe USA. It's no secret, and I am glad to be able to tell you that. I am glad your problem is solved.

Hi all, I searched for an answer to a similar problem and this is the closest I found. My valve was making a high pitched squealing sound at various points and temperatures. I say was, because I followed the above directions with high hopes but now have a vibration issue as well as the high pitched squeal. Euro if you are still on here please provide some guidance. I know these products are tested prior to shipping, but at what temperatures, mine seems to act up most after the water gets good and hot

Thanks,
Bobby