Another Water Pump Question

[Atlbam]

Hi -

My wife and I are in Mae Sot, and are enjoying the start of rainy season. We rent a two story condo, with a kitchen, a shower, and two toilets. We're thinking about getting a water pump because our water pressure drops to nothing when it rains (and also at night after 10pm).

Does anyone have suggestions on how powerful of a pump we need, and how big a resevoir tank we need?

We're also unclear how all three should connect. If we want to draw from the main water line when the water pressure is good, do we somehow switch between drawing from the reservoir tank vs. the main water line or are all three (pump, reservoir, main water line) interconnected? Though this would seem like a fairly straightorward question, we haven't had any luck so far in our searches of the various forum discussions in getting a clear idea of how all three work together. Clearly it is a newbie question, so apologies in advance.

Thanks--we're obviously just starting out on this project and would appreciate any advice you can give.

[Crossy]

Something like this:

As to tank size, if your supply is generably reliable but just goes low pressure at night I suggest a minimum of 250L.

You say you're in a condo, where do you intend putting the tank?

Water is heavy, a full 1000L tank weighs over a ton! Not something you put on a cantilever balcony

[Atlbam]

Hi -

Thanks for replying. The tank will be on the first floor, in the kitchen, so no worries on the weight. I appreciate the diagram! Do you have any recs on wattage for the pump? My next door neighbor has, I believe, a 300 watt pump, but he also runs a small laundrymat and a vietnamese restaurant. We won't need nearly as much water.

Thanks!

[wayned]

I would use at least a 250. I have a 150 in my townhouse in Bangkok and the pressure in the second floor is adaquate but would enjoy a little more.

[Pib]

A 250 watt pump would be enough...something around an 850-1200L tank should provide adequate water reserve.

I use a 250W pump and 850L tank for my two story/3 bathroom house. And believe it or not, just today was the first day in around 5 years living here that the 850L tank was not quite enough water storage with the periodic (but infrequent) water main breaks we have that sometimes last almost a day to repair. There was a main water line break in the moobaan "yesterday" and the security "did not" go around the moobaan telling folks about the break and estimated time for repair like they normally do. Well, late this afternoon our taps stopped putting out water and the water pump was running continuously try to suck water...I was actually taking a shower when the water dried up...I checked my 850L tank and it was dry...this is when we drove over to the water main repair site where five Bangkok water department trucks and a backhoe were still digging/working to repair the line. Had a bunch of neighbors there also as they had run out of water also....everybody is PO'ed security didn't go around a moobaan "yesterday" to tell everyone this was a "major" break and it may be another day before being fixed (the water main burst under a concrete bridge...hard to get to for a fix). This morning the wife had did an abnormally high number of washing machine loads and we had a guest last night who used the shower very liberally last night and this morning...all of sudden our 850L water tank which had been more than adequate for approx. 2 days or normal water usage was not enough. Fortunately, about 3 hours after our tank went dry the water main break was fixed and our tank is full again.

"Do not" setup the system to where you are routinely drawing directly from the soi water line---why would you want to do this on a routine basis?

Let the soi water main feed directly to the tank and let the pump draw from the tank. If the soi water main goes dry and you are still switched to draw from the soi main line then you will need to go outside and switch valves to draw from the tank after you notice your pump is running continuously (getting really hot) because it's trying to suck water when there is no water to suck from the water main. But if the pump is sucking directly from the tank, if the soi water main goes dry, then your pump/water to the house continues to work because its got that tank water to suck from....and if the soi water main is only dry for a couple hours and maybe even a day or two depending on your water usage you won't even notice there was a water main outage because the water was being sucked from your storage tank...and when the soi water main starts working again then it automatically refills/keeps the tank full through use of the float valve in the tank.

[Pib]

Deleted...duplicate to above...my connection to ThaiVisa is acting up.

Edited June 8, 2013 by Pib

[Pib]

Deleted...duplicate to above...my connection to ThaiVisa is acting up.

Edited June 8, 2013 by Pib

[rawhod]

"Do not" setup the system to where you are routinely drawing directly from the soi water line---why would you want to do this on a routine basis?

Because, firstly, as you found out, you will not be aware of the break in the mains supply.

And secondly, after a repair, they do not always purge the dirty contaminated water from the pipe, and your tank will automatically fill with this dirty brown contaminated water and you will not be aware of it until it comes through your house system. You are then left with a tank full of dirty water.

[Pib]

rawhod, on 09 Jun 2013 - 09:07, said:

Pib, on 08 Jun 2013 - 21:25, said:

"Do not" setup the system to where you are routinely drawing directly from the soi water line---why would you want to do this on a routine basis?

Because, firstly, as you found out, you will not be aware of the break in the mains supply.

And secondly, after a repair, they do not always purge the dirty contaminated water from the pipe, and your tank will automatically fill with this dirty brown contaminated water and you will not be aware of it until it comes through your house system. You are then left with a tank full of dirty water.

I expect the dirty water thing could happen, but it's never happened for me...I guess the Bangkok water department in my area takes precautions for that. For example, they open up some fire hydrants closest to the break after the repair for a few minutes to help purge any funky water...if there was any.

And I would prefer not to know about water outages that occur periodically and usually last well less than the daylight hours of one day. Also don't like causing my pump to run and run and run trying to suck water that ain't there...not really an issue if I'm home but I still haven't got it through the wife's brain yet what to do when I'm not around and that happens. I also think its against regulations to hook your lines directly to water mains in residential areas...of course against regulations/laws don't mean much in Thailand. Plus, its not uncommon for the water main pressure to be "so low" trying to suck water from the mains ends up in your pump not getting enough water which causes it to run much longer/get hot and the water output to your residence goes low/has air in it. But even with a low pressure it's more than enough to keep your tank full as it attempts to fill your tank 24/7. No, I'll continue to let my storage tank be my direct source of water.

P.S. I've only used water direct from the lines one time by doing some valve switching...and that was a couple months ago for two days when we had our tank removed to lay new tile in that area around my house. I took this occasion to completely drain/clean the tank which was a very easy job because after 5 years of use there might had been a couple tablespoons of sediment at the bottom...this sediment was approx. 3 inches below the tank outlet to the pump. That could be considered another advantage of a tank as it can allow any sediment to settle below the tank's outlet which means it don't get into the residence...but of course some may say that sediment would continuously contaminate the water in the tank...I'm cool with a little sediment in the tank....I figure that sediment didn't make it to my house.

Edited June 9, 2013 by Pib

[rawhod]

rawhod, on 09 Jun 2013 - 09:07, said:

Pib, on 08 Jun 2013 - 21:25, said:

"Do not" setup the system to where you are routinely drawing directly from the soi water line---why would you want to do this on a routine basis?

Because, firstly, as you found out, you will not be aware of the break in the mains supply.

And secondly, after a repair, they do not always purge the dirty contaminated water from the pipe, and your tank will automatically fill with this dirty brown contaminated water and you will not be aware of it until it comes through your house system. You are then left with a tank full of dirty water.

I expect the dirty water thing could happen, but it's never happened for me...I guess the Bangkok water department in my area takes precautions for that. For example, they open up some fire hydrants closest to the break after the repair for a few minutes to help purge any funky water...if there was any.

And I would prefer not to know about water outages that occur periodically and usually last well less than the daylight hours of one day. Also don't like causing my pump to run and run and run trying to suck water that ain't there...not really an issue if I'm home but I still haven't got it through the wife's brain yet what to do when I'm not around and that happens. I also think its against regulations to hook your lines directly to water mains in residential areas...of course against regulations/laws don't mean much in Thailand. Plus, its not uncommon for the water main pressure to be "so low" trying to suck water from the mains ends up in your pump not getting enough water which causes it to run much longer/get hot and the water output to your residence goes low/has air in it. But even with a low pressure it's more than enough to keep your tank full as it attempts to fill your tank 24/7. No, I'll continue to let my storage tank be my direct source of water.

P.S. I've only used water direct from the lines one time by doing some valve switching...and that was a couple months ago for two days when we had our tank removed to lay new tile in that area around my house. I took this occasion to completely drain/clean the tank which was a very easy job because after 5 years of use there might had been a couple tablespoons of sediment at the bottom...this sediment was approx. 3 inches below the tank outlet to the pump. That could be considered another advantage of a tank as it can allow any sediment to settle below the tank's outlet which means it don't get into the residence...but of course some may say that sediment would continuously contaminate the water in the tank...I'm cool with a little sediment in the tank....I figure that sediment didn't make it to my house.

The first time it does happen, you will be unaware of it.

I am not suggesting that you pull water directly from the mains supply.

Using the configuration shown by "Crossy" you can use the mains supply most of the time when the supply pressure is adequate. When it is inadequate, turning three valves will bring in the tank and pump. It is also prudent to run the tank periodally so as not to leave it stagnent.