Leaking Grohe model 34-436.

[rhoyerjr]

Leaking Grohe model 34-436.
I purchased and installed part 47-111, (thermo element cartridge ($165.00)) based on my local plumbing store recommendation that this should fix a very consistent drip from my Grohe shower faucet. My local plumbing store is normally very reliable but I do not think they know Grohe faucets very well so I am turning to this forum for advice.
While I had the facet disassembled I cleaned and lubricated everything.
I believe my problem may be one of the stop valves. Both of them had some green corrosion which I cleaned off. I also lubricated the o rings. Before I spend any more money and take the time to tear apart the faucet again does anyone have any experience and advice? Perhaps I am missing an adjustment that would stop the leak?

[jimbo]

I am not familiar with Grohe showers. However, I looked at the diagram for your valve on their website. It appears that the thermoelement part 47-111 is just that...the temperature control. For the faucet to drip, water has to be getting TO the thermoelement when it should not be. It looks like the "drip" would be caused by the stop valves ( hot or cold) , items 9 on the diagram, part number 08-355 ( 2 pcs, hot side and cold side).
However, don't go out and buy more parts on my say-so. I am just looking at a diagram for a valve I don't have my hands on. Get someone to look at it in person. Or possibly call Grohe customer service. If they are good, they can help you troubleshoot.

[rhoyerjr]

Thank you Jimbo. I agree with your assesment.
It is very difficult not only find but to get someone to visit the house to repair a leaky faucet.
I'll buy the parts and have another go at it. I can hear the drip at night, it is water torture!
Thank you for your input.

[rhoyerjr]

Replacing the stop valves stopped the leak.

[mike_or]

I am a novice when it comes to plumbing. I have the same leaky grohe shower and I wonder if I should attempt the same fix or get a grohe-aware plumber.

Any advice is appreciated.

[jadnashua]

Call Grohe or e-mail them. I had a faucet that leaked only when the handle was left in a particular position (single handle type). They sent me a new cartridge for free...worth asking, anyways.

[mike_or]

Thanks! Will contact Grohe as suggested

mike

[mike_or]

Hi All,
Grohe's techinical support asked me to replace the stop valves, just as jimbo suggested earlier.

"The stop valves will need to be replaced, this is part number 08.355.000
there is a company called Tapco @ 1800 782 0658 they will take orders and
ship direct.

My question to jimbo and rhoyerjr and others listening in:

Can I, as a novice, replace the stop valves myself or do I need a plumber who knows how to fix Grohe fixtures?

I looked at the fixture and it has only two screws connecting the fixure to the wall. Is it enough to undo these 2 screws, and pull out the fixture in order top replace the stop valves? Do I need any special tools? I think I need to shut off the water main before replacing the stop valves. Anything else I need to worry about?

thanks

[lambtron]

Replacing the stop valves is an expensive way to fix this problem. I am currently working to solve this same problem (a slow leak in my Integrated Grohmix 34-436), but I hope to solve it in a less costly way.

Before I explain my troubleshooting/repair procedure, here's a tip for mike_or: you don't need to shut off the whole house when servicing this valve; just turn off the service stops that are hidden behind the escutcheon. These are the large screws at the extreme left/right of the overall valve assembly. Just turn them 1/4 turn either way (so the slots are vertical instead of horizontal) and you can then dissect the valve to your heart's content without risking a flood.

Due to the architecture of this valve, a slow leak is virtually guaranteed to be caused by a leaky stop valve. Knowing this, my first goal was to determine which of the two (hot vs. cold) stop valves was leaking. To do this, I turned off first the cold, and then the hot service stops. The leaking stopped when I turned off the hot service stop, so I knew then the the leak was coming from the hot stop valve.

Next, I removed and inspected the hot stop valve assembly, Grohe part number 08-355. What I discovered was a worn o-ring on the inner plunger shaft. It is clear that this o-ring, which is the middle of three o-rings on the shaft, is responsible for blocking the water flow when the stop valve is turned off. So, it is likely that the leak can be stopped by simply replacing this o-ring, at a cost of maybe 25 cents, instead of the entire stop valve, at a cost of more than $100! Note: I cleaned the filter screen with a toothbrush under running water while the stop valve assembly was out and totally accessible.

Unfortunately, the Grohe parts list doesn't break out assembly 08-355 into its component parts. To get around this, I removed the worn o-ring and measured it. It measures approximately 7mm inside diameter, 12mm outside diameter, 2.5mm cross section. The o-ring material is not known, but I think any common o-ring material will work as long as the rings are properly lubricated.

Another unfortunate problem is parts availability. None of my local plumbing, auto supply or hardware stores stock this o-ring size. I contacted Grohe and appealed to them for a couple of spare o-rings. They have a good reputation for customer support, so I might get lucky and receive a few from them. If not, I suppose I will order a minimum quantity (i.e., $25 worth) of o-rings from an online supplier; if it comes down to this, I will gladly send, upon receipt of a SASE, some of my surplus o-rings to others in this situation.

[Verdeboy]

Nice job! I can't believe that you can't find the correct size O-ring. I've bought little plumbing repair kits that have a zillion different sizes of O-rings. Maybe the right one is in a kit like that.

Sometimes worn O-rings have stretched a bit. Thus, a slightly smaller one might work. While you're waiting for Grohe, try using something close and see if it works. It's only a few cents, like you said.

[lambtron]

Nice job! I can't believe that you can't find the correct size O-ring.

I couldn't believe it either! I went to Home Depot, Napa Auto and a specialty plumbing supply store, and except for one o-ring I found, none of their in-stock o-rings were even close.

While you're waiting for Grohe, try using something close and see if it works. It's only a few cents, like you said.

That's good advice and exactly what I did. I purchased and installed the closest o-ring I could find, but the leak persisted and the valve exhibited a behavior that indicated a poor o-ring fit (e.g., when valve is shut off it leaks, but back it off, or play with it a little, and the leak flow rate drops to a tolerable level). At the very least I'm hoping Grohe will respond quickly with the exact specification for the o-ring so I can order a replacement and be confident it will be a good fit.

It's a mystery to me why the parts list doesn't call out items like this o-ring. O-rings receive the brunt of the wear and tear from valve operation and they typically will need to be replaced at some point in the life of a valve.

[Lancaster]

As mercenary as it sounds,my thinking is that Grohe figures they will never be able to make any money selling a replacement for that o-ring.You see more and more of this with regards to replacement parts.

I can kind of see their thought process.It costs a lot of money to maintain each part number,and they will never be able to recoup it even if they charge 5 bucks for it.

Sadly,that goes against the old American way of doing business,where repair parts was not intended to be a profit center but was tolerated as a cost of doing business.Now granted Grohe's parent is a German outfit,but more and more USA companies are doing it this way too.Ah I hate to see it happen,but its been going in that direction for 30 years now,I guess we have to learn to love it,or at least live with it..

[Mikey]

If you Google {metric o-rings} you'll get a ton of hits for o-ring suppliers. They normally have a minimum order size, but one of those "zillion o-ring" kits might satisfy it. Most of them also have customer service lines where they might offer advice on what material to use, even to a small customer.

[lambtron]

... one of those "zillion o-ring" kits might [have the o-ring you are looking for]

I searched the Internet high and low but couldn't find a kit with o-rings that are even close to the size I need. In fact, I found only one supplier that lists the needed size (and it isn't available in any of their kits), with a minimum order of $25 plus shipping.

That's the bad news, but I also have good news to report. I mentioned in an earlier post that I had emailed my o-ring query to Grohe customer support. I never received a reply, so I called them and explained my problem. The fellow I talked to never addressed the o-ring issue, but he cheerfully offered to send me two replacement stop valves at no cost to me. As promised, I received them yesterday and plan to install them today. If everything goes well, my shower will be back in business tonight.

As mercenary as it sounds,my thinking is that Grohe figures they will never be able to make any money selling a replacement for that o-ring.

In the end, it appears that Grohe is not witholding the o-ring specification in order to boost profits. Not only that, but I must pass along kudos to Grohe for their top-notch customer support.

Although the leak problem is now apparently resolved, I am still disturbed by the wastefulness of the solution. There may be some valid technical reason for replacing the entire stop valve instead of just the o-ring, but I sense that "the baby is being thrown out with the bath water."

[lambtron]

Final Report:

I installed a new hot stop valve yesterday and the leak is fixed.

Although the cold stop valve wasn't leaking, I did notice some wear on the same o-ring that failed in the hot stop valve. Also, the outsides of both the hot and cold stop valves were discolored and not mirror-smooth like the new stop valves. This deterioration didn't appear to be present on the inner surfaces of the valve cylinders, but these surfaces are difficult to inspect and any degradation of surface smoothness here will lead to rapid o-ring deterioration. For these reasons (and since Grohe sent me a pair of new stop valves) I decided to replace the cold stop valve too.

Summary:

Showerhead leaks in Grohe model 34-436 valves will always be caused by a malfunctioning stop valve (Grohe part number 08-355). More specifically, the cause will be a failed middle o-ring on the inner plunger shaft of the stop valve. This critical o-ring can fail due to abrasion as a result of (1) particles in the water supply passing through the stop valve filter, or (2) degradation of surface smoothness inside the stop valve cylinder, or (3) loss of o-ring lubricant.

The life of the critical o-ring can be extended by periodically cleaning the stop valve filters and lubricating the inner shaft's o-rings.

When the critical o-ring fails, stop valve replacement is the recommended cure unless (1) a properly fitting o-ring replacement can be found, and (2) it is known that the inner surface of the stop valve cylinder is in excellent, mirror-smooth condition.