Considerations for shower hot water heater

[funlovinkid]

I've been having endless problems controlling the temperature while showering, and I've decided to try to figure out the best solution so that I only have to fix this problem once.  I have two supply lines that feed the shower fixture: one is normal (unheated) supply, and the other is supplied by the water heater mounted on the wall above the shower ceiling.  I know that some heaters are designed to be physically accessed and controlled during the course of the shower (i.e. mounted on the wall inside the shower stall), but any water heater mounted in my current location above the ceiling will obviously be inaccessible as well.  I've been controlling the temperature using the shower hot/cold control knobs, but it's been a constant struggle.  Also, I notice that the cold water supply line which feeds the heater is also the source for the shower cold water valve, which might significantly change the supply of water available to the heater whenever I open the cold water valve, resulting in temperature fluctuations.

 

I've done some reading about "open-loop" vs. "closed-loop" water heater designs, and which design might be best for a shower.  After having lived in Thailand for over 10 years, it seems that this is a very common problem.  Wondering if anyone out there has already been through this?

[soi3eddie]

You've been living in Thailand for 10 years and still want a hot shower? ????

 

For guests at my place, I have a hot water heater (3 settings) and find that the middle setting is comfortable for them. Ambient temperature varies very little here so it never needs to be adjusted.

[EVENKEEL]

Our water pressure is so low in morning we can't use the hot water. 40 gal plastic garbage can and scooper solves the problem.

[lopburi3]

30 minutes ago, funlovinkid said:

I know that some heaters are designed to be physically accessed and controlled during the course of the shower

Almost all the shower heaters are so designed here.  I hope you are at least using a multi point heater as normal heaters are also not designed to have a tap on output.

 

Have never had much luck with temp control in hospitals/hotels and such here and suspect this is due to the cold water actually being almost hot most of the year.

[4MyEgo]

Always buy the hot water heater at the maximum, i.e. 6.0 that way your water is always hot, even with the dial in the middle, anything lower than that and you will be having cold showers this winter.

 

I say the above because we have 3 bathrooms, 2 of them have 3.5's and ours 6.0, the kids using the 3.5's compaing in winter that the water is not hot enough so we allow them to use ours and will change them to 6.0 when they need changing.

[Buffy Frobisher]

I put a solar water tank up on the roof when I built the house 17 years ago and have had piping hot water in every room ever since, even on cloudy days in the middle of the monsoon. Sure as heck saved on the power bills too - I reckon it easily paid for itself in 12-18 months. Worth considering?

[lopburi3]

5 minutes ago, 4MyEgo said:

Always buy the hot water heater at the maximum, i.e. 6.0 that way your water is always hot, even with the dial in the middle, anything lower than that and you will be having cold showers this winter.

 

I say the above because we have 3 bathrooms, 2 of them have 3.5's and ours 6.0, the kids using the 3.5's compaing in winter that the water is not hot enough so we allow them to use ours and will change them to 6.0 when they need changing.

Actually there is a more logical 4.5KW model from most now and that should be fine for most locations (upcountry mountains an exception) and should not require re-wire of house.

[The Fugitive]

19 minutes ago, EVENKEEL said:

Our water pressure is so low in morning we can't use the hot water. 40 gal plastic garbage can and scooper solves the problem.

I shower outside using a saucepan.

[In Full Agreement]

40 minutes ago, soi3eddie said:

You've been living in Thailand for 10 years and still want a hot shower? ????

 

For guests at my place, I have a hot water heater (3 settings) and find that the middle setting is comfortable for them. Ambient temperature varies very little here so it never needs to be adjusted.

 

I've read William Randolph Hearst was a pretty controlling host but  I don't think even he controlled the water temperature of his guests.   ???? ????

 

[scorecard]

42 minutes ago, soi3eddie said:

You've been living in Thailand for 10 years and still want a hot shower? ????

 

For guests at my place, I have a hot water heater (3 settings) and find that the middle setting is comfortable for them. Ambient temperature varies very little here so it never needs to be adjusted.

Agree. In fact, like many folks, I discovered years ago that hot showers just made me sweat more and produce BO.

 

Cold or with a very low setting so just the chill is taken off the water & after being under the water a few seconds I turn back to full cold. Works for me.

[Mark Nothing]

My condo developer installed an el cheapo hot water heater that did not function.  During the course of a ten minute shower the water intermittently fluctuated between hot and cold. 

 

After trying other products that were not much better, the solution was a Steibel Eltron German made hot water heater.  Excellent product.  Works correctly every time.  Installed under sink in one bathroom and in ceiling in the other.  15 years and functioning flawlessly.

 

 

[lopburi3]

22 minutes ago, Mark Nothing said:

the solution was a Steibel Eltron German made hot water heater. 

Actually it has been my experience that such were the problem at hotels and hospitals as could not adjust/hold temp.  But have no experience with them in years so maybe they fixed such issues.

[cmjc]

Hosepipe around the roof edge gives you free hot water daily, but I've used a 20 litre plastic jerry can in the garden for several years.

 

In the hot season I only use it to wash clothes.

 

Neighbours have copied my high-tech method now ????

[Moonlover]

57 minutes ago, scorecard said:

Agree. In fact, like many folks, I discovered years ago that hot showers just made me sweat more and produce BO.

 

Cold or with a very low setting so just the chill is taken off the water & after being under the water a few seconds I turn back to full cold. Works for me.

Cold showers are reckoned to boost the immune system as well. I even used to finish off with a short cold burst back in UK where the water is really cold!

 

P.S. I never get sick.

[scorecard]

31 minutes ago, cmjc said:

Hosepipe around the roof edge gives you free hot water daily, but I've used a 20 litre plastic jerry can in the garden for several years.

 

In the hot season I only use it to wash clothes.

 

Neighbours have copied my high-tech method now ????

Well done...

[VocalNeal]

2 hours ago, EVENKEEL said:

Our water pressure is so low in morning we can't use the hot water. 40 gal plastic garbage can and scooper solves the problem.

Panasonic Jet pump heater with an internal pump. You can shower anytime.

May even be others brands with similar in HomePro/Global etc. Even one on shopee.

[EVENKEEL]

2 minutes ago, VocalNeal said:

Panasonic Jet pump heater with an internal pump. You can shower anytime.

May even be others brands with similar in HomePro/Global etc. Even one on shopee.

But with low pressure in the morning I don't see how a different unit would help because we have village water, not from a well or tank.

[ThomasThBKK]

3 minutes ago, EVENKEEL said:

But with low pressure in the morning I don't see how a different unit would help because we have village water, not from a well or tank.

Ever thought of installing a watertank that gets filled from village water and an additional pump between water tank and water supply that makes sure u have enough pressure?

 

village water -> pump -> water tank -> pump -> water supply line 

Edited December 6, 2022 by ThomasThBKK

[VocalNeal]

9 minutes ago, EVENKEEL said:

But with low pressure in the morning I don't see how a different unit would help because we have village water, not from a well or tank.

It will take low pressure,  It needs less than 1 psi supply, and boost it to give a good shower pattern from the showerhead. 

 

If you have no water flow then it won't help. You need a little ...

Edited December 6, 2022 by VocalNeal

[Lacessit]

The OP is trying to control temperature of two streams, two variables. If he shuts off his cold water supply, he will only have one variable.

On both my water heaters, there is a temperature control dial. I set it to the desired water temperature, cold water in, warm or hot water out. Basic Hitachi and Toshiba 4.5 kW.

The water temperature in the condo shower remains unchanged, because my GF is too short to reach the temperature control. In her house, it goes back and forth because she prefers colder water.

Mounting a water heater above the ceiling doesn't sound too smart to me, inaccessible for either temperature control, or if the heater develops a fault.

KISS.

[EVENKEEL]

8 minutes ago, ThomasThBKK said:

Ever thought of installing a watertank that gets filled from village water and an additional pump between water tank and water supply that makes sure u have enough pressure?

 

village water -> pump -> water tank -> pump -> water supply line 

You're right, that could solve it. Just never put much thought into it, our method works.

[FriendlyFarang]

You either get something like this: https://shopee.co.th/GROHE-GROHTHERM-1000-NEW-ก๊อกผสมยืนอาบThermostat-34143003-i.706241291.16220007754?sp_atk=00cf18f4-56aa-4f3a-b4a6-e5aae59be5ba&xptdk=00cf18f4-56aa-4f3a-b4a6-e5aae59be5ba

You connect it to the hot/cold lines and set it to the desired temperature

 

Or you get something like this: https://shopee.co.th/TOSHIBA-Water-Heater-(4-500W-White)-DSK45ES5KB-i.3850059.1969808941?sp_atk=69307b59-8059-4755-9da5-20c90ece092a&xptdk=69307b59-8059-4755-9da5-20c90ece092a

You simply connect it to your cold line and set it to the desired temperature

 

With both of these, if the water pressure changes, it will automatically regulate the water flow to keep the temperature stable. It does of course have its limitations, if the water pressure changes too quickly it might not be able to regulate fast enough.

[OneMoreFarang]

Get something like this, problem solved.

 

 

[Lacessit]

6 minutes ago, OneMoreFarang said:

Get something like this, problem solved.

 

 

Makes four variables out of the current two. More components to break down. KISS.

[OneMoreFarang]

3 minutes ago, Lacessit said:

Makes four variables out of the current two. More components to break down. KISS.

It puts the temperature regulation as near as possible to the water output.

Different temperature "cold" and "hot" can come in and it will make a constant temperature out of it - even if the input temperatures change.

[Lacessit]

1 minute ago, OneMoreFarang said:

It puts the temperature regulation as near as possible to the water output.

Different temperature "cold" and "hot" can come in and it will make a constant temperature out of it - even if the input temperatures change.

I get that, but why add an extra layer of cost and complexity when the solution is as simple as reduction to one variable?

[OneMoreFarang]

26 minutes ago, Lacessit said:

I get that, but why add an extra layer of cost and complexity when the solution is as simple as reduction to one variable?

I offered one simple possible solution.

I didn't say that is the only solution.

[Lacessit]

1 hour ago, OneMoreFarang said:

I offered one simple possible solution.

I didn't say that is the only solution.

I would not call it simple when four variables are created, when only one variable exists in the solution I proposed.

[Dante99]

OP and almost everybody else will get temperature variations because the input pressure is not constant.  Unless you put in a system to provide constant input pressure this problem will persist.  

There are expensive solutions but generally not considered worth the cost.

17 hours ago, funlovinkid said:

After having lived in Thailand for over 10 years, it seems that this is a very common problem.  Wondering if anyone out there has already been through this?

For most it is just not a big deal to simply live with it.  

 

 

 

 

 

 

 

 

 

 

 

 

[funlovinkid]

15 hours ago, Lacessit said:

The OP is trying to control temperature of two streams, two variables. If he shuts off his cold water supply, he will only have one variable.

On both my water heaters, there is a temperature control dial. I set it to the desired water temperature, cold water in, warm or hot water out. Basic Hitachi and Toshiba 4.5 kW.

The water temperature in the condo shower remains unchanged, because my GF is too short to reach the temperature control. In her house, it goes back and forth because she prefers colder water.

Mounting a water heater above the ceiling doesn't sound too smart to me, inaccessible for either temperature control, or if the heater develops a fault.

KISS.

Hmm, hadn't thought about just leaving the cold water valve off, and setting the temperature (once) on the water heater.  Thanks!