Water pump problems

[hocuspocus]

I have an Hitachi type water pump to supply my house from a water tank and in my view it is short cycling when a tap is opened partly in the house. In the past my experience with pump supplied water there is a pressure vessel to reduce this short cycling and when this pressure vessel loses its pressure then the short cycling increases. The end result is that the pump itself will wear out faster or the electrical side will burn out. We have had someone to attempt repair of this problem but they just changed the float system in the tank (the cut out when the tank has no water). Yes the pressure has improved and the short cycling has stopped when the tap is opened fully but in my mind but it is still short cycling. Has anyone had this problem? What sort of time period should there be before the pump kicks in? Probably no so much a time period but more of a cut in pressure and a cut out pressure but with the absence of a pressure gauge this is hard to tell. Thanks in advance.

[KhunBENQ]

Move to DIY forum?

[Crossy]

Short-cycling is almost certainly that the pump pressure tank has become waterlogged (it needs an air space to work properly).

It's an easy fix, depends on exactly what pump you have.

[Sutty]

Ours kicks in after 15 or so seconds of turning tap on then remains on till tap is turned off.

[Crossy]

Ours kicks in after 15 or so seconds of turning tap on then remains on till tap is turned off.

Yeah, that's how I would expect it to work, if you reduce the flow the pump will eventually start cycling, the period being related to the size of the air reservoir.

[Sutty]

Ours kicks in after 15 or so seconds of turning tap on then remains on till tap is turned off.

Yeah, that's how I would expect it to work, if you reduce the flow the pump will eventually start cycling, the period being related to the size of the air reservoir.

Agreed when we use water filter that's what happens it cycles but that's normal and we only use the filter once a day to top up fresh water indoors. Reducing the flow to other outlets isn't a problem showers have a reducer fitted which is never moved up or down once it was set pump stays on constantly when showers used, toilets well it only takes 15 secs to refill so pump very rarely kicks in, sinks in bathroom again have reducers fitted so we get the flow we want again not moved since set and again pump remind on when taps open. Sink in kitchen same type of configuration just enough flow for what is required again pump stays on.

[Sutty]

Hi just a follow up tried as you said reducing flow to a trike via tap not short cycling on constantly at pump.

[noise]

Short cycling on my tank only incurs when the cut off psi is too close to the city water pressure. My pumps default settings are 20 psi differential and recommended setting to be 30 psi on and 50 psi off. City pressure runs around 35 psi . If the cut off is 40 psi, then constant cycling. That is why I maintain the 50 psi cut off

If, for some reason, city water is turned off and I exhaust the tank, the pump suck air into the line and then will run continuously. When water comes back on and the tank refills, I have to bleed the air out. The pump will sometime still run continuously until the lines in the house are bled, also. And I sometimes need to reset the 30 - 50 psi settings.

I do not understand the reducer comments (didn't really think about them) because my water heaters require a certain flow (psi) to turn on. Low pressure/flow and no hot water.

[Sutty]

Short cycling on my tank only incurs when the cut off psi is too close to the city water pressure. My pumps default settings are 20 psi differential and recommended setting to be 30 psi on and 50 psi off. City pressure runs around 35 psi . If the cut off is 40 psi, then constant cycling. That is why I maintain the 50 psi cut off

If, for some reason, city water is turned off and I exhaust the tank, the pump suck air into the line and then will run continuously. When water comes back on and the tank refills, I have to bleed the air out. The pump will sometime still run continuously until the lines in the house are bled, also. And I sometimes need to reset the 30 - 50 psi settings.

I do not understand the reducer comments (didn't really think about them) because my water heaters require a certain flow (psi) to turn on. Low pressure/flow and no hot water.

I use reducers as we don't need high pressure from any taps only hot water we have is from showers (Mrs only she gets cold in morning) showers have a booster in built to give a better flow to head so as I pump water to shower then shower boosts again I reduce water flow to shower still achieving a good power shower therefore saving water in the process. Same as the rest of taps I reduce flow to all that is required again resulting in water saving whilst maintaining a working flow. Hope that clears it up a bit. I'm all about saving water always been that way I recycle my grey waste for garden and veg.

[MaiChai]

I posted on another thread: pump differences. On my pump on the expansion vessel there is a sticker saying what the pressure should be and to check it yearly; it has a bicycle style valve so u can refill it. I checked it with the pressure checker I use for motorbike/car tires. Another issue is small stones and debris getting in and blocking things up; have a clean out. Then there is the pressure switch which can go out of calibration; these have a screw that can be adjusted or if it's not working properly, replaced. Overall I found my pump reliable; just the expansion vessel and pressure switch gave me issues.