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shower heater liters per min water flow questions


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hi everyone

 

my new Grundfos water pump based in our home in BKK delivers 19 liters per minute, but the shower water heater restricts it down to 8 liters per minute.

I heard that all water heaters in Thailand are restricted to 8 liters per minute? anyone know if this is true or not and can anyone suggest a shower water heater model that can allow more?  I realize that if we push more water through it might not heat the water sufficiently however I am not looking for a very hot shower, just to take the chill of the water and have more water flow.

I have also been  told that I cant go higher then 3500Watt otherwise I need to recable to the fuse box. 

 

thanks in advance to all helpful suggestions. 

 

here are my testing results

 

testing water flow per min - results
With heater connected cold water
8 liters 
With heater connected hot water
8 liters 
With no heater connected but with hand shower
16 liters
Tap only
19 liters

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20 minutes ago, VocalNeal said:

Install  a storage heater instead of an instant heater.

thanks we considered that too, but we are a bit space limited so would prefer the current setup

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42 minutes ago, flipper2222222 said:

thanks in advance to all helpful suggestions. 

Your power cable can almost certainly allow for a a more powerful heater, however that will not increase the flow. You could however add a second heater and run that in parallel to the first one, though not the most elegant solution it is simple to implement and guaranteed to at least increase the flow by 50% at least quite possibly almost 100% more

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46 minutes ago, jaizan said:

Dismantle the heater, find the restrictor and modify it.

I thought it was the narrow size of copper pipes inside that was restricting it? do you think there is a specific part that can be removed?

currently we have a sharp wh55 installed 

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As far as increasing the heater size, higher wattage more amps, you will need to advise the cable size and the circuit breaker rating, assuming there is a seperate breaker for the heater circuit. Having this information might help, however you need review the flow capability of the heater and knowing the inlet temp of the water supply can also be a consideration. 

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On 1/3/2022 at 3:21 PM, sometimewoodworker said:

Your power cable can almost certainly allow for a a more powerful heater, however that will not increase the flow. You could however add a second heater and run that in parallel to the first one, though not the most elegant solution it is simple to implement and guaranteed to at least increase the flow by 50% at least quite possibly almost 100% more

thanks STWW,

that is a very good logical solution, I have asked a contact at Siebel Eltron to see if one of their partners can do this for us. 

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19 hours ago, Artisi said:

As far as increasing the heater size, higher wattage more amps, you will need to advise the cable size and the circuit breaker rating, assuming there is a seperate breaker for the heater circuit. Having this information might help, however you need review the flow capability of the heater and knowing the inlet temp of the water supply can also be a consideration. 

I have been advised that the wire to the current heater is supplied by 2.5 mm cable and the circuit breaker is 16 Amp, anyone know if this will allow another 3500 W heater in parallel?

 

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20 minutes ago, flipper2222222 said:

I have been advised that the wire to the current heater is supplied by 2.5 mm cable and the circuit breaker is 16 Amp, anyone know if this will allow another 3500 W heater in parallel?

 

3500W = 14A

2.5mm cable is 16A max.

 

So not unless you want to melt your 2.5mm cables.

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1 hour ago, BritManToo said:

3500W = 14A

2.5mm cable is 16A max.

 

So not unless you want to melt your 2.5mm cables.

 

1 hour ago, BritManToo said:

3500W = 14A

2.5mm cable is 16A max.

 

So not unless you want to melt your 2.5mm cables.

Humm. That would not even be correct we’re you to run both heaters at full power for an hour at a time,

they would certainly get the temperature rather higher than is recommended but melting the cable is a gross overstatement.

 

If you were to put a meter on your water heater you will be hard put to get a reading anything like the maximum. 75% of total is most likely to be the maximum  you would get and in general 50% is more likely.

 

Of course adding a separate supply or upgrading the existing is the best option.

 

also your you rating for 2.5mm cable is either too high, if the cable is Enclosed in conduit in an insulated wall or too low if the cable is clipped to the wall

A7A61FA2-FB22-49EF-A1B3-B2FFD7E3FD71.thumb.jpeg.420b91cbeffeb436c18b8266dc1fe82e.jpeg

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2 hours ago, sometimewoodworker said:

 

Humm. That would not even be correct we’re you to run both heaters at full power for an hour at a time,

they would certainly get the temperature rather higher than is recommended but melting the cable is a gross overstatement.

 

If you were to put a meter on your water heater you will be hard put to get a reading anything like the maximum. 75% of total is most likely to be the maximum  you would get and in general 50% is more likely.

 

Of course adding a separate supply or upgrading the existing is the best option.

 

also your you rating for 2.5mm cable is either too high, if the cable is Enclosed in conduit in an insulated wall or too low if the cable is clipped to the wall

A7A61FA2-FB22-49EF-A1B3-B2FFD7E3FD71.thumb.jpeg.420b91cbeffeb436c18b8266dc1fe82e.jpeg

I guess it wouldn't be too hard to wire a separate heater to the fuse box on a separate circuit, but the contact I had at Seibel Electron answered today with this. 

 

"Our service and installation partners have not been doing parallel installations for some time now as in the past there were too many issues associated with the precises dimensioning of the pipes. Small mistakes in required pipe lengths can result in unsatisfactory flow through the 2 separate units."

 

anyone know a company in BKK could setup such a parallel system and wire from the fuse box?

 

cheers

 

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2 hours ago, flipper2222222 said:

I guess it wouldn't be too hard to wire a separate heater to the fuse box on a separate circuit, but the contact I had at Seibel Electron answered today with this. 

 

Quote

"Our service and installation partners have not been doing parallel installations for some time now as in the past there were too many issues associated with the precises dimensioning of the pipes. Small mistakes in required pipe lengths can result in unsatisfactory flow through the 2 separate units."

anyone know a company in BKK could setup such a parallel system and wire from the fuse box?

cheers

That is somewhat understandable as what they are saying is that you would have to do a considerable amount of calculation, together with pressure tests if yo wanted to have exactly the same flow through the two heaters along with the same output temperatures.

 

However all that is unnecessary since you just want more flow so if one heater is supplying more water at a lower temperature than the other does it really matter? It’s going to mix in the shower head anyway.

 

Our showers do not use the supplied restrictors to control input flow as we have them setup to be able to take hot and cold water. 
0756971B-06E6-44F3-A6F5-F0C6D7747EC9.thumb.jpeg.e9297d37e130cc5153b06c63cba4e5b4.jpeg

 

so it would be trivial to add a splitter to the mixer tap, then feed two heaters and add a the opposite joiner to the shower unit.

 

However you will probably have to design the plumbing yourself as I doubt that it would be easy, or possible, to explain the setup to a Thai plumber. You will get the “can not do” “Thai plumbing is different to foreign plumbing” answers.

 

Getting a second power feed setup and the shower unit installed will be easy, though of course you will be considered crazy.

 

But don’t try to get a single installer to both fit the shower and electrical supply and also plumb in the joint in feed/out feed supply. 

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5 hours ago, sometimewoodworker said:

If you were to put a meter on your water heater you will be hard put to get a reading anything like the maximum. 75% of total is most likely to be the maximum  you would get and in general 50% is more likely.

Just a FWIW our showers can technically draw 27A, SWMBO has just had a shower. Total power used in the house was 20.3A when she finished the power being used is 3.74A. So the shower was using a little over 60% of the possible consumption. Also the input water temperature is low now so we are using more heat than usual 

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On 1/3/2022 at 11:21 AM, sometimewoodworker said:

Your power cable can almost certainly allow for a a more powerful heater, however that will not increase the flow. You could however add a second heater and run that in parallel to the first one, though not the most elegant solution it is simple to implement and guaranteed to at least increase the flow by 50% at least quite possibly almost 100% more

The main issue at hand is the restrictors are sized to handle a specific amount of flow in order to heat the water properly as they have a very small capacity tank internal. Getting a larger heater is the appropriate approach after you've determined how much flow and temp you want or need. the numbers posted as part if the test done are fairly significant already  although at what temp???  You have generally a flow restrict at the base of the heater where the flex tubing connects and you may also have a flow restrictor inside the hand held shower head that can often be removed 

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1 hour ago, Dan O said:

The main issue at hand is the restrictors are sized to handle a specific amount of flow in order to heat the water properly as they have a very small capacity tank internal. Getting a larger heater is the appropriate approach after you've determined how much flow and temp you want or need. the numbers posted as part if the test done are fairly significant already  although at what temp???  You have generally a flow restrict at the base of the heater where the flex tubing connects and you may also have a flow restrictor inside the hand held shower head that can often be removed 

The point that you are missing is that the vast majority, if not all, of the normal instant shower heaters have the same maximum flow. The more powerful heaters are able to raise the the output temperature from a lower input temperature, few if any have a higher flow rate than the lower powered ones.

 Very few actually make it easy to find the flow as you will see from earlier posts.

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14 hours ago, Dan O said:

The main issue at hand is the restrictors are sized to handle a specific amount of flow in order to heat the water properly as they have a very small capacity tank internal. Getting a larger heater is the appropriate approach after you've determined how much flow and temp you want or need. the numbers posted as part if the test done are fairly significant already  although at what temp???  You have generally a flow restrict at the base of the heater where the flex tubing connects and you may also have a flow restrictor inside the hand held shower head that can often be removed 

thanks, I will have a closer look at these area of the current system, I found a ladder hidden at home so will try again as from the  ground I was struggling to get the cover off 

 

I am after more pressure rather than hot temperature, agreed doubling the flow might make the water not quite warm enough.

 

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2 minutes ago, flipper2222222 said:

wont this mean when the 30 liters is finished I will end up with a cold shower? would prefer the instantaneous as the warm water is ongoing. 

30l is a lot of water for a shower, 56l tank costs 12kbht.

 

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15 hours ago, sometimewoodworker said:

That is somewhat understandable as what they are saying is that you would have to do a considerable amount of calculation, together with pressure tests if yo wanted to have exactly the same flow through the two heaters along with the same output temperatures.

 

However all that is unnecessary since you just want more flow so if one heater is supplying more water at a lower temperature than the other does it really matter? It’s going to mix in the shower head anyway.

 

Our showers do not use the supplied restrictors to control input flow as we have them setup to be able to take hot and cold water. 
0756971B-06E6-44F3-A6F5-F0C6D7747EC9.thumb.jpeg.e9297d37e130cc5153b06c63cba4e5b4.jpeg

 

so it would be trivial to add a splitter to the mixer tap, then feed two heaters and add a the opposite joiner to the shower unit.

 

However you will probably have to design the plumbing yourself as I doubt that it would be easy, or possible, to explain the setup to a Thai plumber. You will get the “can not do” “Thai plumbing is different to foreign plumbing” answers.

 

Getting a second power feed setup and the shower unit installed will be easy, though of course you will be considered crazy.

 

But don’t try to get a single installer to both fit the shower and electrical supply and also plumb in the joint in feed/out feed supply. 

hopefully you can follow my answers to you questions and points this way


yes totally agree supplying different pressures or temperatures between the heater is not of great importance


did you remove the supplied restrictors yourself?


agreed, mai dai is a very common response in the country

 

agree again, they probably already think I am crazy, so let's keep reinforcing that at least I will be consistent 🙂


I am getting to see that tasks are looked upon in a very piecemeal kind of way here, maybe it helps keeping the unemployment rate so low ????
 

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Shower heater in Thailand - a problem? The usual 3,500 W should be enough for most of the days with exception of few days in winter months and in the North(/East) when the flow can be reduced to get a warmer water. 

 

And if somebody has a steel vessel filter outside exposed to sunshine - especially now when the days are very bright during daytime - the water gets hot free of charge.  

 

BTW,  in order to be more resistive to COVID and/or any similar disease (flu), one should rather get hardened by cool water. 😃  

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2 hours ago, flipper2222222 said:

did you remove the supplied restrictors yourself?

32B3404C-63C0-4918-8A79-C0B8465BE039.thumb.jpeg.a1b8381471864feaf356193466b60479.jpeg
I either removed them or didn’t fit them.

 

2 hours ago, flipper2222222 said:

I am getting to see that tasks are looked upon in a very piecemeal kind of way here, maybe it helps keeping the unemployment rate so low ?

It is not that the tasks are piecemeal, it is that fitting the shower heater and wiring is a known job so you will have absolutely no problem getting someone to do that for you.

 

But designing the plumbing though really simple is totally outside anyones experience so, 1) you are going to have a really tough time explaining what you want 2) you may think that you have explained it but will be amazed by the incredibly inventive ways a Thai plumber can get it completely wrong because they really really did not understand  3) if you understand my explanation it’s a trivial job to do it yourself.

 

if you do decide on the 2 heaters option I strongly recommend getting them fitted side by side as that will make your final Frankenstein plumbing job easier.

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5 hours ago, Saanim said:

Shower heater in Thailand - a problem? The usual 3,500 W should be enough for most of the days with exception of few days in winter months and in the North(/East) when the flow can be reduced to get a warmer water. 

 

And if somebody has a steel vessel filter outside exposed to sunshine - especially now when the days are very bright during daytime - the water gets hot free of charge.  

 

BTW,  in order to be more resistive to COVID and/or any similar disease (flu), one should rather get hardened by cool water. 😃  

haha , yes the BTW is good advice, one day for me .... maybe

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2 hours ago, sometimewoodworker said:

32B3404C-63C0-4918-8A79-C0B8465BE039.thumb.jpeg.a1b8381471864feaf356193466b60479.jpeg
I either removed them or didn’t fit them.

 

It is not that the tasks are piecemeal, it is that fitting the shower heater and wiring is a known job so you will have absolutely no problem getting someone to do that for you.

 

But designing the plumbing though really simple is totally outside anyones experience so, 1) you are going to have a really tough time explaining what you want 2) you may think that you have explained it but will be amazed by the incredibly inventive ways a Thai plumber can get it completely wrong because they really really did not understand  3) if you understand my explanation it’s a trivial job to do it yourself.

 

if you do decide on the 2 heaters option I strongly recommend getting them fitted side by side as that will make your final Frankenstein plumbing job easier.

more great advice on both topics, will try first one (yes we have one of those twirly knobs thingos thought the restrictor was in the internals of the unit, that should be easy to remove), review and then possibly the second. thanks again.  

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37 minutes ago, flipper2222222 said:

more great advice on both topics, will try first one (yes we have one of those twirly knobs thingos thought the restrictor was in the internals of the unit, that should be easy to remove), review and then possibly the second. thanks again.  

It is the usual way to reduce the flow so as to allow the water temperature to rise when the input temperature is too low. In my case, as in the picture above, I have a mixer tap that controls the flow so these are redundant for temperature control.

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On 1/5/2022 at 6:23 PM, sometimewoodworker said:

32B3404C-63C0-4918-8A79-C0B8465BE039.thumb.jpeg.a1b8381471864feaf356193466b60479.jpeg
I either removed them or didn’t fit them.

 

It is not that the tasks are piecemeal, it is that fitting the shower heater and wiring is a known job so you will have absolutely no problem getting someone to do that for you.

 

But designing the plumbing though really simple is totally outside anyones experience so, 1) you are going to have a really tough time explaining what you want 2) you may think that you have explained it but will be amazed by the incredibly inventive ways a Thai plumber can get it completely wrong because they really really did not understand  3) if you understand my explanation it’s a trivial job to do it yourself.

 

if you do decide on the 2 heaters option I strongly recommend getting them fitted side by side as that will make your final Frankenstein plumbing job easier.

today I removed the external tap as you illustrated above and still only got 8 Liters in the test bucket. 

as you suggested the Frankenstein approach might be the only way?

 

do you think there is another internal restrictor in the heater?

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1 hour ago, flipper2222222 said:

today I removed the external tap as you illustrated above and still only got 8 Liters in the test bucket. 

as you suggested the Frankenstein approach might be the only way?

 

do you think there is another internal restrictor in the heater?

If you can get a higher flow using the shower head you are using with the heater when connected directly to the house supply without the heater then yes.

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On 1/11/2022 at 8:47 PM, sometimewoodworker said:

If you can get a higher flow using the shower head you are using with the heater when connected directly to the house supply without the heater then yes.

Frankenstein here we come 555

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