Mains adapter

[Mel]

As the philosophy of this lovely forum is that there is no such thing as a stupid question, I will ask this with impunity from pointing and laughing.
Whale mains adapter ( I.e hose from tap to pump inlet, no aquaroll). We have always turned on the pump switch at the control panel; light comes on when we draw water, light goes off when we stop. Everyone happy.
This weekend OH set up as usual, but next day turned off the pump switch (to remove hose from tap briefly, reason irrelevant) but then forgot to turn it back on again. Water continued to flow whenever we opened the taps. This went on all weekend including two showers, so not just residual water in the system.
This is on a Unicorn Valencia S3.
So, with these mains adapters, do you not need to turn the pump switch on?
Thanks in advance for all elucidation.
Mel

 

[Thingy]

Got me thinking that one. Isn the pump just to draw water from the barrel. Dont know for sure so I stand to be laughed at too. We recently had a discussion about mains direct to van as opposed to using the float in a half filled aquaroll. But it does seem to confrim the worries that people had about the mains pressure.

 

[Damian]

Hi Mel, no, in your case you do not need to use the pump, but some vans do, even with the mains adapter

 

[ProfJohnL]

.... But it does seem to confrim the worries that people had about the mains pressure.

Which worries are you suggesting are confirmed?

It seems that Mel's. pressure reducing unit in the mains water hose is doing its job. as the mains water supply provides the necessary pressure, there is no need for the pump circuit to be activated.

 

[Thingy]

Which worries are you suggesting are confirmed?

In the thread I was referring to, we were discussing a direct connection as opposed to the float/aquaroll method. A number of concerns related to the supplied pressure in case of a problem within the caravan, i.e. a leak. If the pump isnt activating, and the tap system itself is the only thing holding the water back, a split or leak could surely therefore become a constant flow within the caravan.

A number of members stressed that they preferred the latter float method for safety. I seem to recall there was little trust in the pressure reducing mechanism within the waterline. If I am not mistaken Prof, you were part of that discussion.

 

[ProfJohnL]

Hello Thingy,
I certainly was part of that discussion, and I am very aware of the concern about the possibility of a prv failure, and it's consequences inside a caravan. Though in practice such failures are a very very low number. There are a greater number of problems where there is insufficient flow, and that can be due to a number of other factors.

I do think the use of a float valve in an water barrel is an even better solution, as it relieves restricted site supply limitations, and it removes any concerns about prv failures.

But I don't see that Mel's posting confirmed that concern, it was a description of what had happened. It was due to a misunderstanding of how the system worked and not a disaster or failure.

 

[Thingy]

But I don't see that Mel's posting confirmed that concern, it was a description of what had happened. It was due to a misunderstanding of how the system worked and not a disaster or failure.

Agreed, but it does highlight the amount of pressure that the mains will supply. If you consider most site water supplies, the flow at the fawcett is about the same as those in a domicile, and you surely would have some concern in resepct of the plastic pipes and fittings considering also the way these caravans are thrown together.

I initially purchased a waterline but after consideration and the previous discussion I reverted to the float. What I was referring to about confirmation (possibly the wrong choice of description) was the potential damage if the pressure reducer failed.

 

[ProfJohnL]

Agreed, but it does highlight the amount of pressure that the mains will supply. If you consider most site water supplies, the flow at the fawcett is about the same as those in a domicile, and you surely would have some concern in resepct of the plastic pipes and fittings considering also the way these caravans are thrown together.

I initially purchased a waterline but after consideration and the previous discussion I reverted to the float. What I was referring to about confirmation (possibly the wrong choice of description) was the potential damage if the pressure reducer failed.

I fully appreciate the common concern if a PRV were to fail and allow full pressure through. Caravan fittings are designed for a normal working pressure of only 1.5 to 2Bar, so allowing them to see mains water pressure is certainly not a good idea. That is not in question.

I used to frequently have discussions with Carver's service engineers, and, I was only aware of only ONE PRV failure letting mains pressure through. That was detected by the Cascade 2 heater continually releasing water from its Pressure Relief Valve. It did also cause some leaks on taps. Even with its rarity I would still prefer the system using a local water storage for the other reasons explained previously. There were other types of failure mainly reports of low flow rates, which is resolved by using local water tank and caravan pump.

 

[chrisn7]

We used the Whale direct connector for many years in our old van, which was from '98, and the block was still going strong in 2016 when we traded it. So, I could say it was totally reliable. It did not require a pump to operate.

However the spring pressure in the PRV is overcome as soon as a tap is opened, but the PRV only cracks open a little, so the flow in the van will be less than the usual pumped flow. This has been mentioned many times over the years. I spoke to Whale and they could change the spring in the unit, but the downside is then a higher pressure in the van with associated risk of leaks. Essentially a good idea, but still needs refining even after all these years.