Water heater questions

[TexasRanger]

Having a house built at the moment and the plan is to have a water heater fitted under the bathroom sink that will supply warm water to the sink and shower.

We have a similar set up in our other house and our current rental place.

The builder foreman is confused as to what constitutes a warm water heater (kruang tam nam oon) and a hot water heater (kruang tam nam ron). He has now got me confused as I thought they were all the same but with varying wattage.

I went to a shop today where they said anything above 3kw that can heat more than just a shower is a hot water heater and 3kw and below is just for a shower only.

They also tried to sell me the type with a copper pipe as opposed to the cylinder. Pics attached.

Anyone know of any pros and cons of the 2? I must say ive never had a problem with the cylinder type with heater control on the front. Is there one I should stay away from?

Cheers.

[TexasRanger]

Another thought, I guess the hot water pipe should be of the PE type, is that correct terminology?

[holeyman1]

if even the foreman is confused, I'd say forget both (most likely they wouldn't know which wire goes where, grounding etc)

best to scrap those 2 & get a water boiler (the ones with the > 80ltr tank types, use lpg to heat up water or thereabouts)

less likely to get electrocuted.!

but if you must, imo the cylinder one is better

[bankruatsteve]

Those appear to be multi-point heaters - which means separate cold/hot feeds to the shower/sink/etc. The hot water feed would be with copper or the approved PVC (I forget the name - green?). The single point heaters are the ones that you put on the wall in the shower and heat on demand with no need for separate hot water plumbing. Do not proceed until your builder understands whichever option you go with and if it's with the multi-point heater make sure he REALLY understands both the plumbing and electrical requirements.

Edit: The 3kw level for whatever is ridiculous and not a determination for the type of unit.

Edited February 5, 2014 by bankruatsteve

[pancakeman]

The warm water heaters are hooked directly to the shower head and there is only 1 pipe. So you have a cold water pipe come out of the wall, go into the warm machine, then a pipe comes out and into the shower heat.

Hot water machine you will have 2 pipes coming out at wall (cold and a hot pipe from the hot machine), and then use a mixing shower head.

If you like a really hot shower (especially in the 'cold' season) you really want a hot machine, at least 4000-5000 watts.

Note: Be aware that hot water machine use a lot of power and will require larger than standard wiring. For example 4000W heater will require 4sqmm wiring, and 8000W heater will require 6sqmm wiring....if they are like most Thai electricians they will try to install 1.5 or 2.5mm wiring so be careful

Edited February 5, 2014 by pancakeman

[TexasRanger]

Thanks for the replies, the wiring size is something I need to check, the electrician seems up to code but I'll check anyway.

The boiler in the roof isn't an option. So I guess I'll just need to get a couple of multipoints.

[Gsxrnz]

Our house has the same setup- one heater situated under the sink and also provides hot water to the shower and bath.

The only problems I have is that I need to run the shower for perhaps 2 minutes to get the hot water delivered at the shower head, and secondly, if anybody is in the shower and the sink tap is used for hot water, you suffer reduction of pressure and temperature at the shower head.

Have you considered installing a separate heater at each location? Obviously more expensive in the shore term, but removes the confusion over what sort to get, how to plumb it, and how to wire it.

Maybe over the long term the savings of electricity and water would make up the difference. i.e less wattage required at both locations, less loss /wastage of water/electricity through having to run the shower to get warm water fed through, plus leaving wasted hot water in the pipes when shut off.

[TexasRanger]

Our house has the same setup- one heater situated under the sink and also provides hot water to the shower and bath.

The only problems I have is that I need to run the shower for perhaps 2 minutes to get the hot water delivered at the shower head, and secondly, if anybody is in the shower and the sink tap is used for hot water, you suffer reduction of pressure and temperature at the shower head.

Have you considered installing a separate heater at each location? Obviously more expensive in the shore term, but removes the confusion over what sort to get, how to plumb it, and how to wire it.

Maybe over the long term the savings of electricity and water would make up the difference. i.e less wattage required at both locations, less loss /wastage of water/electricity through having to run the shower to get warm water fed through, plus leaving wasted hot water in the pipes when shut off.

To be honest I hadn't considered thst, but on reflection it might not be a bad idea as our shower takes about a minute to heat up too.

It's been a long time since I used a stand alone electric shower and can't remember if the hot water was instantaneous or not.

[Gsxrnz]

Our house has the same setup- one heater situated under the sink and also provides hot water to the shower and bath.

The only problems I have is that I need to run the shower for perhaps 2 minutes to get the hot water delivered at the shower head, and secondly, if anybody is in the shower and the sink tap is used for hot water, you suffer reduction of pressure and temperature at the shower head.

Have you considered installing a separate heater at each location? Obviously more expensive in the shore term, but removes the confusion over what sort to get, how to plumb it, and how to wire it.

Maybe over the long term the savings of electricity and water would make up the difference. i.e less wattage required at both locations, less loss /wastage of water/electricity through having to run the shower to get warm water fed through, plus leaving wasted hot water in the pipes when shut off.

To be honest I hadn't considered thst, but on reflection it might not be a bad idea as our shower takes about a minute to heat up too.

It's been a long time since I used a stand alone electric shower and can't remember if the hot water was instantaneous or not.

They're pretty much instantaneous, plus it's guaranteed to be much quicker than the water running (in my case) 8 metres from under the sink. The other advantage is no loss of heat if (read: when) the missus decides to run the hot water at the sink while you're showering. Mine has a sadistic streak and does it for fun anyway!

Plus, if at some future stage one of the units craps out (as they're bound to do), you'll always have hot water available at the other unit in the interim.

[Crossy]

We have two 'RedRing' multipoint heaters like the one on the left in the OP, they're under the sinks in the bathrooms.

They do work well, yes, there is a warm-up time but it's a few seconds, no issues with sadistic wife turning on the sink, bathroom door is locked

I have noticed that the tube clogs more easily than the tank type we had in our last place, so for that reason I wouldn't recommend.

[TexasRanger]

We have two 'RedRing' multipoint heaters like the one on the left in the OP, they're under the sinks in the bathrooms.

They do work well, yes, there is a warm-up time but it's a few seconds, no issues with sadistic wife turning on the sink, bathroom door is locked

I have noticed that the tube clogs more easily than the tank type we had in our last place, so for that reason I wouldn't recommend.

Thanks for that, it's nice to know about the clogging, something I would never have considered and certainly something I wouldn't want to deal with.

[stoneyboy]

We have two 'RedRing' multipoint heaters like the one on the left in the OP, they're under the sinks in the bathrooms.

They do work well, yes, there is a warm-up time but it's a few seconds, no issues with sadistic wife turning on the sink, bathroom door is locked

I have noticed that the tube clogs more easily than the tank type we had in our last place, so for that reason I wouldn't recommend.

Clogs with what exactly ?

[pancakeman]

I have noticed that the tube clogs more easily than the tank type we had in our last place, so for that reason I wouldn't recommend.

If the ~1/4" heating pipes are getting "clogged" with your fresh water supply I would think something is wrong more than just a problem with the heater.

All the filter meshes on your taps or butt-sprayers must be totally clogged too?

[Crossy]

We had a sand like material in the gauzes, could even have been sand.

Installed a polyester crunchy-bits filter in the incoming supply which seems to have solved that issue, but still get some lime-scale in the heater tubes.

[Gonsalviz]

The warm water heaters are hooked directly to the shower head and there is only 1 pipe. So you have a cold water pipe come out of the wall, go into the warm machine, then a pipe comes out and into the shower heat.

Hot water machine you will have 2 pipes coming out at wall (cold and a hot pipe from the hot machine), and then use a mixing shower head.

If you like a really hot shower (especially in the 'cold' season) you really want a hot machine, at least 4000-5000 watts.

Note: Be aware that hot water machine use a lot of power and will require larger than standard wiring. For example 4000W heater will require 4sqmm wiring, and 8000W heater will require 6sqmm wiring....if they are like most Thai electricians they will try to install 1.5 or 2.5mm wiring so be careful

To further this,Make sure they use the correct circuit breaker. I have a 12,000 watt 13.2 kva water heater. First they tried a 20 amp breaker, then a 32 amp breaker. Brrrraaaapp. Wrog answer. Try 63 amp. Kva/ 220 volts will give you the correct amperage.

[TexasRanger]

The warm water heaters are hooked directly to the shower head and there is only 1 pipe. So you have a cold water pipe come out of the wall, go into the warm machine, then a pipe comes out and into the shower heat.

Hot water machine you will have 2 pipes coming out at wall (cold and a hot pipe from the hot machine), and then use a mixing shower head.

If you like a really hot shower (especially in the 'cold' season) you really want a hot machine, at least 4000-5000 watts.

Note: Be aware that hot water machine use a lot of power and will require larger than standard wiring. For example 4000W heater will require 4sqmm wiring, and 8000W heater will require 6sqmm wiring....if they are like most Thai electricians they will try to install 1.5 or 2.5mm wiring so be careful

To further this,Make sure they use the correct circuit breaker. I have a 12,000 watt 13.2 kva water heater. First they tried a 20 amp breaker, then a 32 amp breaker. Brrrraaaapp. Wrog answer. Try 63 amp. Kva/ 220 volts will give you the correct amperage.

Thanks, they have already been instructed. Cheers.