Accumulator tank

[canalrunna]

The water system on my narrowboat has a Jabsco 2.9 water pump which pulsates when the taps are turned on slow. I am thinking of adding an accumulator into the system to hopefully stop the problem. Can anyone offer any information as to a suitable accumulator tank that should do the job.

[Tony Brooks]

Basically the largest possible that is stated as for potable water and at least 5 litres. However, you will be wasting your money if you are only doing it to stop cycling with a partially opened tap. The pump cycles because the pump output is greater than  the flow from the tap so the pressure rises and the pump turns off. Then the pressure falls as water flows from the tap so the cycle repeats. All it will do is to make the length of the on and off periods longer.

[Sea Dog]

9 hours ago, canalrunna said:

The water system on my narrowboat has a Jabsco 2.9 water pump which pulsates when the taps are turned on slow. I am thinking of adding an accumulator into the system to hopefully stop the problem. Can anyone offer any information as to a suitable accumulator tank that should do the job.

Despite the fact that Jabsco say the Par Max 2.9 doesn't need an accumulator, in reality it does make a difference.  When you turn the tap on, water will run for a few seconds before the pump kicks in, and when you turn off the tap the pump will run on for a few seconds whilst the accumulator recharges. As @Tony Brooks says above, if you leave a tap on low, the pump will kick in and out, but it'll be less frequent and hence less of a pulsation with an accumulator fitted downstream of the pump. Contrary to Tony's sage advice of 5 litres plus, I'd still  go with Jabsco's matching little black jobbie, which is either 1 or 2 litres. Well, I say I'd go, but actually that's what is paired with my Par Max 2.9 and, I suspect, many, many others with similar Jabsco based set ups. It works just fine.

[Tony Brooks]

I suspect a potable Screwfix/Toolstaion accumulator will be cheaper than a Jabsco one with the marine mark up. The domestic ones tend to be larger than many so-called marine ones.