Has anyone tried thermostatic shower controls with a with tankless
(demand) water heaters to avoid temperature fluctuations? Any
comnents/ thoughts?

Thanks!

On 2007-03-17, wrote:

Has anyone tried thermostatic shower controls with a with tankless
(demand) water heaters to avoid temperature fluctuations? Any
comnents/ thoughts?

I haven't tried it but I have a couple thoughts. Temperature
fluctuations from a tankless heater are of two kinds: the "cold water
sandwich" from stopping and restarting the flow, and the smaller
temperature fluctuations when demand changes and the burner has to
equilibrate with the new flow rate.

A thermostatic valve isn't going to do anything for the cold water
sandwich, since there is no hot water available. As for the demand
change temperature fluctuations, they last only a seconds or two. So
the question is what is the response time of a thermostatic valve? If
the response time is smaller than a couple seconds, it should shorten
the fluctuation.

I've decided to try putting a small (2.5 gallon) electric tank in
series with my tankless heater, to see if it will average out both
kinds of temperature fluctuations. I just installed in yesterday
though, so it's too soon to tell.

Cheers, Wayne

On 17 Mar 2007 11:08:18 -0700, wrote:

Has anyone tried thermostatic shower controls with a with tankless
(demand) water heaters to avoid temperature fluctuations? Any
comnents/ thoughts?

Thanks!

Ahhh, luxury, I love it.

On Mar 17, 1:08�pm, wrote:
Has anyone tried thermostatic shower controls with a with tankless
(demand) water heaters to avoid temperature fluctuations? *Any
comnents/ thoughts?

Thanks!

If you had a regular tank this probably wouldnt be a issue.

feed tankless to regular tank and enjoy endless stable temp hot water

On Mar 17, 8:42 pm, " wrote:
On Mar 17, 1:08?pm, wrote:

If you had a regular tank this probably wouldnt be a issue.

feed tankless to regular tank and enjoy endless stable temp hot water

Uh....ahhh...ummm...what?!?!?!

On Mar 19, 2:09?pm, "CyBrShRk" wrote:
On Mar 17, 8:42 pm, " wrote:

On Mar 17, 1:08?pm, wrote:

If you had a regular tank this probably wouldnt be a issue.

feed tankless to regular tank and enjoy endless stable temp hot water

Uh....ahhh...ummm...what?!?!?!

water suppy in, ----------- tankless acts as pre heater-----------
regular how water tank, with regu;lar tank getting water preheated by
tankless first you now have a endless supply of stable temp hot water

On Mar 17, 6:37 pm, Deke wrote:
On 17 Mar 2007 11:08:18 -0700, wrote:

Has anyone tried thermostatic shower controls with a with tankless
(demand) water heaters to avoid temperature fluctuations? Any
comnents/ thoughts?

Thanks!

Ahhh, luxury, I love it.

Deke,

What brand of water heater/ valves are you using?

Thanks

On 2007-03-17, wrote:

Has anyone tried thermostatic shower controls with a with tankless
(demand) water heaters to avoid temperature fluctuations? Any
comnents/ thoughts?

You know, I started looking into this, and now I don't understand what
a "thermostatic" shower valve does. I thought it would adjust the
relative flow of the incoming hot and cold water supplies to provide
the desired temperature, regardless of the incoming temperatures. But
I have read a number of the manuals which state that if you adjust
your water heater temperature, you have to recalibrate the
"thermostatic" valve. In which case it doesn't seem very thermostatic
to me.

Are there any thermostatic shower mixing valves that will maintain the
set temperature given fluctuating hot water supply temperatures?

Cheers, Wayne

On Mar 20, 2:30 pm, Wayne Whitney wrote:
On 2007-03-17, wrote:

Has anyone tried thermostatic shower controls with a with tankless
(demand) water heaters to avoid temperature fluctuations? Any
comnents/ thoughts?

You know, I started looking into this, and now I don't understand what
a "thermostatic" shower valve does. I thought it would adjust the
relative flow of the incoming hot and cold water supplies to provide
the desired temperature, regardless of the incoming temperatures. But
I have read a number of the manuals which state that if you adjust
your water heater temperature, you have to recalibrate the
"thermostatic" valve. In which case it doesn't seem very thermostatic
to me.

Are there any thermostatic shower mixing valves that will maintain the
set temperature given fluctuating hot water supply temperatures?

Cheers, Wayne

Not that Iam aware of they will not heat or make up for lack of hot
water. If you are going to run the system you describe it will cost
you a fair amont of electricity

On 2007-03-20, jim wrote:

Not that Iam aware of they will not heat or make up for lack of hot
water. If you are going to run the system you describe it will cost
you a fair amont of electricity

No, no, obviously I don't expect the valve to provide water outside of
the range of temperatures supplied to it. But some "thermostatic"
valves say they don't adjust for fluctuating supply temperature, just
supply pressure, e.g. some Deltas. That doesn't seem very
thermostatic to me.

Cheers, Wayne

On Mar 20, 3:33�pm, Wayne Whitney wrote:
On 2007-03-20, jim wrote:

Not that Iam aware of they will not heat or make up for lack of hot
water. If you are going to run the system you describe it will cost
you a fair amont of electricity

No, no, obviously I don't expect the valve to provide water outside of
the range of temperatures supplied to it. *But some "thermostatic"
valves say they don't adjust for fluctuating supply temperature, just
supply pressure, e.g. some Deltas. *That doesn't seem very
thermostatic to me.

Cheers, Wayne

I have seen ones with LCD readout you set the desired temperature too,
I was told they cost near a grand

On Mar 20, 3:48 pm, " wrote:
On Mar 20, 3:33?pm, Wayne Whitney wrote:

On 2007-03-20, jim wrote:

Not that Iam aware of they will not heat or make up for lack of hot
water. If you are going to run the system you describe it will cost
you a fair amont of electricity

No, no, obviously I don't expect the valve to provide water outside of
the range of temperatures supplied to it. ?But some "thermostatic"
valves say they don't adjust for fluctuating supply temperature, just
supply pressure, e.g. some Deltas. ?That doesn't seem very
thermostatic to me.

Cheers, Wayne

I have seen ones with LCD readout you set the desired temperature too,
I was told they cost near a grand

Why are you going to all of this trouble as most taps are pressure
balanced and will keep within 2.2 degrees of set temp

wrote:
On Mar 19, 2:09?pm, "CyBrShRk" wrote:

On Mar 17, 8:42 pm, " wrote:


On Mar 17, 1:08?pm, wrote:

If you had a regular tank this probably wouldnt be a issue.

feed tankless to regular tank and enjoy endless stable temp hot water

Uh....ahhh...ummm...what?!?!?!


water suppy in, ----------- tankless acts as pre heater-----------
regular how water tank, with regu;lar tank getting water preheated by
tankless first you now have a endless supply of stable temp hot water


Yes, and set the tankless to MAX temp, plumb it to cold water in on
disconnected electric DHW tank.

DHW outlet temp should then be a consistent 125F, and the L Bacteria
doesn't get a foothold

Wayne Whitney wrote:
On 2007-03-20, jim wrote:

Not that Iam aware of they will not heat or make up for lack of hot
water. If you are going to run the system you describe it will cost
you a fair amont of electricity

No, no, obviously I don't expect the valve to provide water outside of
the range of temperatures supplied to it. But some "thermostatic"
valves say they don't adjust for fluctuating supply temperature, just
supply pressure, e.g. some Deltas. That doesn't seem very
thermostatic to me.

Cheers, Wayne

then they are not thermostatic, they are pressure balanced, which is
code nowadays

I have a hans grohe shower valve, from the despot, that I absolutely
worship. You set it once. Ever.

A real thermostatic valve ought to work well for your app. It 'should'
fire up full hot, then start mixing as the hot water comes up. I notice
mine has a little spike if you are under it before it hits its temp,
just a half second of overshoot, long enough to reach for the valve
instinctively, but not long enough for you to turn it.

ji
Why are you going to all of this trouble as most taps are pressure
balanced and will keep within 2.2 degrees of set temp


that would be true if the supply temps were always the same, which they
never are. The cold water gets colder, the hot gets cooler, temp drifts
down. Only a thermostatic valve would be even close.

On Mar 21, 8:37?am, Robert Gammon wrote:
wrote:
On Mar 19, 2:09?pm, "CyBrShRk" wrote:

On Mar 17, 8:42 pm, " wrote:

On Mar 17, 1:08?pm, wrote:

If you had a regular tank this probably wouldnt be a issue.

feed tankless to regular tank and enjoy endless stable temp hot water

Uh....ahhh...ummm...what?!?!?!

water suppy in, ----------- tankless acts as pre heater-----------
regular how water tank, with regu;lar tank getting water preheated by
tankless first you now have a endless supply of stable temp hot water

Yes, and set the tankless to MAX temp, plumb it to cold water in on
disconnected electric DHW tank.

DHW outlet temp should then be a consistent 125F, and the L Bacteria
doesn't get a foothold- Hide quoted text -

- Show quoted text -

Dont power off regulaR TANK! otherwise a period away say a day would
leave cool water and no way to heat it.

Use tankless as preheater, and standard tank for stable endless hot
water

On 2007-03-20, Wayne Whitney wrote:

But some "thermostatic" valves say they don't adjust for fluctuating
supply temperature, just supply pressure, e.g. some Deltas.

OK, I contacted Delta today for some clarification. The issue is that
Delta's thermostatic valves (17T series and 18T series) have a warning
in the manual that if you adjust the temperature of the hot water
supply, you may need to recalibrate the thermostatic cartridges. The
answer Delta gave me was that the valves are thermostatic with respect
to small fluctatuations in supply temperature (a few degrees) but not
in response to large fluctatuations in supply temperature (tens of
degrees).

Cheers, Wayne