Water temperature hard to control in shower

[Smarty]

I have a Kohler single lever temperature balancing shower valve which prevents scalding since it supposedly senses and compensates for water demand changes elsewhere in the house. The problem is that the valve is extremely sluggish in responding to the user's manual adjustment, and therefore, trying to get the water temperature to the right mix of hot and cold is very time consuming.

If I make a first guess at where to set it and wait for 30 or 45 seconds, the temperature will stabilize, but is often too cold or too warm. If I then adjust the valve to a hotter or colder setting, it eventually reaches a new setting, again taking maybe 30 or 45 seconds to do so.

Most of the time I can hit the right setting on the 2nd guess. Sometimes a third and final adjustment is required, again taking another 30-45 seconds.

Throughout the entire adjustment period, I am typically standing in very cold or very hot water, waiting for an adjustment to stabilize.

I assume this is ***NOT*** the way the valve is supposed to behave. I've taken the value apart hoping to find springs or other thermal compensators which could be adjusted or replaced. There appears to be no user adjustable parts, with the exception of a high temp limit stop which restricts the valve rotation beyond a comfortable upper temperature range.

Whatever mechanism Kohler uses to sense and react to manual valve changes seems to be outrageously slow. I can't believe this is the way the valve is supposed to work. It is also an expensive (over $100) part for just the valve itself (with no trim kit) so I expected it to be a deluxe item.

I welcome any thoughts of how this should be serviced? Many thanks in advance.

Smarty

[Bob F]

I suspect that you are just dealing with a problem of low volume shower heads. Because it is low volume, it takes awhile to get new water from the valve to the head. If you take off the showerhead, does the water get there fast?

[garmo]

In general it would take at most 10-15 secs for the water to leave the valve, travel through the pipes to the showerhead. Most likely the pressure balancing unite that is tucked inside the valve is starting to fail. If you set the water temp and flush the toilet and the temp in the shower increases noticeably, this would be the part to replace. If you have the common single handle shower valve, the part number is

500520 $42.50, unless you purchased the valve after 1997, the it is free under your warranty. Time to replace 10 minutes.

-g

Smarty wrote:

[Smarty]

Thanks very much. The specific valve I have is the Kohler K-304 shown at:

The valve body alone cost me about $100 about 5 years ago and Kohler now lists the replacement part at $92.50. Are you saying that the valve is still under a free replacement warranty?

Many thanks again, Smarty

[Smarty]

Thanks Bob,

It is definitely a low flowrate showerhead, but there is also a diverter to all the same valve to control the water flow to a spout, and this flowrate is very fast. The valve is extremely sluggish when used either with the showerhead or diverted to the spout.

Smarty

[Bob F]

You got me then. Does the water take a long time to even show up when you turn it on?

Bob

[Bob F]

Most manufacturers seem to offer a "lifetime" warrantee these days.

Bob

[Smarty]

No Bob, the water seems to immediately flow from the shower head (or the spout) as soon as the valve is turned on. The temperature regulator is the really sluggish part. It's as if the valve has to overcome some friction, spring pressure, or some other warm-up delay before it responds to make a temperature change..

[HeyBub]

Disassemble the shower head. It should be obvious what it is that makes the shower head a "low-volume" one.

Disable that part and evaluate the results.

If you can pin the problem on the low-volume shower head, your shivering will be, according to some, in support of the environment. A small price, indeed, to pay for saving the children.

Or, you could turn on the shower while you go through your pre-shower ritual (shuck robe, step on scale, get fresh towel, etc.). It the water's not right, adjust and repeat ritual.

[Mark]

its a long shot, but make sure the hot and cold supply are not reversed... Mark

[Bob F]

I guess my next step would be to disassemble the valve and lubricate the moving parts. Or ask a plumber as a last resort.

Bob

[Smarty]

I did disassemble the valve to the extent that I could, and found a "cartridge" which I must assume gets replaced as an assembly. My next move will be to see if I can get warranty replacement since it is not too old, and has worked this way since installation.

Thanks Bob to you and other members of this newsgroup for your kind assistance.

Smarty

[David Combs]

My shower has separate hot and cold valves, maybe 5' off the floor, with the shower-head at maybe 7' (or 6.5').

That two-foot distance is what, I guess, leads to the delay between twisting a valve and the water hitting me.

I've seen the back-end of the shower (someone had to open the wall in the adjacent room, happened to be opposite the valves), and the two valves' output mixed together right there at the height of the valves.

QUESTION: wouldn't it have been better had the valve outlet-pipes gone on up to the shower-head *separately*, and then mixed there instead?

Wouldn't that shrink the delay to about zero?

And, these days, how do they plumb showers?

David

[Bob F]

Excellent Idea, although probably not compatable with today's pressure balancing valves. You could also use a smaller diameter pipe to the head.

Bob

[Smarty]

I posted a similar thread a few weeks ago, since my Kohler temperature balancing valve (a mere $100 marvel of engineering) can (and often does) take 30 to 45 seconds to respond to a manual change in the setting of the temperature handle.

The valve also controls temperature of water discharged a short distance below the valve through a tub spout, when the diverter is pushed to the tub position rather than the shower position. In both cases (tub spout at high volume flow a few inches below the valve and also shower discharge at low volume 5 feet above the valve), the reaction time is terribly slow. A replacement valve works the same way.

I would call this a crummy design, no more and no less. Shame on Kohler and shame on me for spending so much and expecting this brand to be superior or even equal to cheaper valves.

Smarty