Carver cascade / low water pressure

[ccaravan]

Hi All,

First post - any advice welcome!

We have a Lunar Premiere clubman and have just replaced the boiler Carver Cascade 2 GE (old one was disconnected / partly in pieces so assumed redundant).

Everything seems to work and we get hot and cold water through the sink and shower, the only issue is the water pressure (both hot and cold are very poor).

This might be a bit of a daft question but we're not sure how good the water pressure should actually be for such an old model! It really is a trickle - we were never expecting Niagra falls but it's not really enough for the shower to work (hard to describe).

Would replacing the submersible water pump make any difference? I would have thought the cold water would at least come through at a faster rate.

Thank you in advance!

 

[Dustydog]

Welcome to the forum.
Submersible pumps are prone to failure at the worst possible times so as a rule of thumb carry a spare. Buy a new one of the highest out put compatible with your system.
Check all the connections from pump to taps looking for leaks, kinked pipes or even easier semi blocked filter which may be fitted in line.
The external connection to the caravan may have a little o ring so it's worth changing that too.
Let us know what you find.

 

[DaveA1]

Welcome to the Forum. I had a similar thing on my old van. Check the pipe from the pump to the van, mine had split next to the pump, water was circulating in the container. Also had a problem with the hose fitting to the external connector, small terry clip fixed that.

 

[Hutch]

Welcome, CCaravan, check also the tap heads the little unscrewable filter, on the exit. Checked mine after noticing the flow was a bit low and the mesh was all clogged up. 15 minutes in vinager and all clean again.

 

[ccaravan]

That you everyone for the really quick responses! When I get home I'll see what I can find filter wise.

How would I find out which strength of submersible pump our boiler can cope with? I'll start with a google!

Thanks again,

 

[ProfJohnL]

That you everyone for the really quick responses! When I get home I'll see what I can find filter wise.

How would I find out which strength of submersible pump our boiler can cope with? I'll start with a google!
L)of water
Thanks again,

Hello Ccaravan,

Welcome to the forum. Let s get some terminology coret first of all. The Carver Cascade is only a water heater, it is not a pump. If you have a Carver pump it will be called Crystal you can use any caravan pump with the Cascade.

The Cascade is a heater not a "boiler" as it is not designed to boil water.

The Cascade is a storage water heater that holds about 2 Gallons (9 L) of water. It has a gas fired burner which is thermostatically controlled, Some models ( Cascade GE or Cascade Rapide) also have a main electric immersion heater, which is controlled separately to the gas system. Which ever method you use to heat teh water it will take about 15 to 25 minutes before the tank will be warm enough to use. You can use both gas and electric heating together to speed up the heating period. Once filled with water the tank remains full and to get hot water out you must be able to push cold water in. The heater should be drained at t eend of the holiday and alway before storage to prevent any possibility of frost damage. You should be able to find downloadable copies of the operating instructions at arcsystems.biz

Based on your description of the symptoms, if both hot and cold systems are only producing a dribble, then it suggests the problem lies with the with pump or the cold water inlet pipework.

 

[DaveA1]

Go onto the Towsure web site, they have at least 100 to look at, prices are good to WOW

 

[ccaravan]

Thanks for all the advice! I've been having a look around at alternative pumps, I have a reich 12v 18ltr per min one at the moment - I might have a tinker with it tomorrow to see if the seals are tight enough at the 'submersible end'.

Could there be a problem with the pressure switch or is that likely to be unrelated?

 

[ProfJohnL]

Thanks for all the advice! I've been having a look around at alternative pumps, I have a reich 12v 18ltr per min one at the moment - I might have a tinker with it tomorrow to see if the seals are tight enough at the 'submersible end'.

Could there be a problem with the pressure switch or is that likely to be unrelated?

Can you tell us if when a tap is open if the pump repeatedly runs for a moment and then stops, untill the tap is closed?

 

[ccaravan]

The submersible pump seems to run continually regardless of whether the taps and on or off (I've tried both hot and cold).

Cold water is 'reasonable', a steady flow at least (would take a long while to fill a sink). The hot water is a dribble at best.

 

[ProfJohnL]

The submersible pump seems to run continually regardless of whether the taps and on or off (I've tried both hot and cold).

Cold water is 'reasonable', a steady flow at least (would take a long while to fill a sink). The hot water is a dribble at best.

If I remember correctly I think you told us you have a pressure switched system. If the pump is running continuously then it means the pressure switch is not turning off because the system is not properly pressurising.

Now I do wonder if you have an air lock in the submersible pump. To get rid of any air locks in the pump, when you change the water barrel, after dropping the pump in teh barrel, just disconnect the hose from the side of the caravan for a few seconds, then reconnect it This allows the water to rise through the pump eliminating any air lock in the impeller chamber.

If that is not the solution then the symptoms are worrying. I would look at the pump hose, this might be split as has already been suggested. This would certainly lead to low pressure and flow.

If that is ok then the next stage is the water inlet. some have a non return valve fitted. If this jammed almost closed, it will restrict the flow but it does not explain why the pressure switch isnt working it would just take longer to build up the pressure before turning off

The problem needs to be rectified, becasue if a submersible pump is allowed to run continuously with out significant water flow, or it runs dry, then the motor is in danger of overheating and the heat will distort the pump housing and shaft seals ultimately letting water into the motor. - bye bye pump.

 

[ccaravan]

Thanks again for the advice. I 'wiggled' the pump a little away from the opening outside and lots of water spurted out everywhere at what seemed like quite high pressure - thinking the pump might be alright (pressure wise at least) just need to work out why it runs constantly and the pressure is being lost somewhere on its journey...

 

[Gafferbill]

..........it is a known problem that the cold water inlet to the Carver heater can cause problems.
It contains a non return valve and this can fail to open due to lack of use or old age.......this restricts the water flow.
You may need to replace it ...........it is situated at bottom right hand corner when looking at rear of heater.

See this replacement

 

[ccaravan]

Thank you again!

Another symptom - I used the cold water and it ran hot for quite a while, assume this also points towards the non return valve?

 

[Damian]

Rather than guessing and it taking for ever to get the problem sorted, why not get a mobile engineer to look at it for you ?

 

[Hutch]

Because, that costs money,
Ask a question, get an answer, try this, try that, and eventually something works, and its all sorted, thats part of the help of the Forum.
Hutch.

 

[Damian]

Quote " Because, that costs money,"
So does replacing parts that are not the cause !!!
As does causing more damage by not knowing how to replace parts properly !!

Whilst I agree that the forum is a good place to gain information, without actually being at the persons van and seeing what is happening, at most the advice is guesswork.

An engineer having a supply of parts available is able to reduce the down time of the equipment and provide a safe repair of the defective part or parts.

 

[ProfJohnL]

..........it is a known problem that the cold water inlet to the Carver heater can cause problems.
It contains a non return valve and this can fail to open due to lack of use or old age.......this restricts the water flow.
You may need to replace it ...........it is situated at bottom right hand corner when looking at rear of heater.

See this replacement

A faulty NRV on the water heater would only affect the hot water side. The symptom for a pressurised system would be turn on the hot tap, and you get a rush of water as the air cap in the tank d pushes the water out, but then in a matter of seconds the flow would reduce to a dribble. The fact the op has poor flow on the points to a problem on the cold side.

 

[ProfJohnL]

Thank you again!

Another symptom - I used the cold water and it ran hot for quite a while, assume this also points towards the non return valve?

Not necessarily. The symptom suggests you may have a shower with a mixer valve with a separate flow control, If the mixer valve on the shower is set to a temperature then it may allow hot water to back flow through the cold pipework. The reason you can get this flush of hot water is that you fill the heater with cold water, but when it is heated, the water expands, and generates an increased pressure. There is an air cap in the heater which is designed to accommodate the expanding water, and the air cap will act like a spring, so when a tap is opened the air cap will push hot water out until pressure drops back to the pressure of the cold water, when the pump takes over.

I cannot be certain, but this revelation suggests to me its unlikely the heaters NRV is not faulty. The solution to prevent the hot water mixing into the cold, is to make sure the shower mixer valve is always left turned to full cold, or to have Non return valves fitted into both hot and cold feed pipes to the shower mixer.

We still have not got to the bottom of your problem, which you believe is low water flow at the taps. I think this needs to be quantified. Perhaps your expectations are more than what the system can actually achieve. After the initial surge of hot water, how long does it take to fill a 1 litre jug at each tap?

 

[Gafferbill]

..........it is a known problem that the cold water inlet to the Carver heater can cause problems.
It contains a non return valve and this can fail to open due to lack of use or old age.......this restricts the water flow.
You may need to replace it ...........it is situated at bottom right hand corner when looking at rear of heater.

See this replacement

A faulty NRV on the water heater would only affect the hot water side. The symptom for a pressurised system would be turn on the hot tap, and you get a rush of water as the air cap in the tank d pushes the water out, but then in a matter of seconds the flow would reduce to a dribble. The fact the op has poor flow on the points to a problem on the cold side.

I was responding to the quote below by the OP [bold text] and I was not addressing his other points that his pump runs continuously and inadequately which are separate issues...................

The submersible pump seems to run continually regardless of whether the taps and on or off (I've tried both hot and cold).

Cold water is 'reasonable', a steady flow at least (would take a long while to fill a sink). The hot water is a dribble at best.

 

[ProfJohnL]

Hello Gaffer, In ccaravan's first post he wrote

"

Hi All...Everything seems to work and we get hot and cold water through the sink and shower, the only issue is the water pressure (both hot and cold are very poor)...

Strangely this post does not appear at the head of this thread, but I had to find it through the member search feature. It is his very first post.

This indicates he has issues with pressure and I assume flow on both hot and cold systems.

I have not totally discounted the possibility of a problem on the heaters NRV, but as both hot and cold are not up to expectation, the common factor is the cold water supply.

In my last post I have asked the OP to measure the flow rates (time to fill 1 litre) and that will tell us if the flows are significantly down on what would be typical 2 to 4 litres per min at the taps (based on extensive testing when I was working).

The fact the hot system does have an extra NRV and extra length of pipe add additional restriction to the hot and means the steady state hot and cold flows are likely to be a bit different.

Its my suspicion there is some form of restriction on the cold flow, which will affect the hot as well so that locates the problem before the cold splits to feed the water heater.

I do wonder if his caravan has had an inline water filter at some time, and perhaps this has leaked its Carbon content into the pipework, causing blockage problems in both hot and cold?

 

[Dustydog]

http://www.practicalcaravan.com/forum/technical/53763-carver-cascade-low-water-pressure#423195
All been suggested before Prof. Hopefully the OP will give us more info and do the measuring of flow rate as you suggest. Are you missing any other posts. Every time PCv boffins do an upgrade things go wrong

 

[ProfJohnL]

Hello Dusty,

(edit) How annoying some of these spelling correctors can be see the intended word followed by the auto corrected ones in brackets.

I know it may be splitting hairs, but what you suggested was a blocked filter, which would give rise to the OP's problems, and is simple to resolve, I.e. replace the filter.

The different point I have made is that I have witnessed many instances of water systems invaded by the carbon particles from a filter. These bits find their way into a!sorts of valves and can get lodged either rendering the valve useless or at least impeding it's correct action. If this has happened then it's a total strip down to get at all the possible valves, which is a much bigger job.

This problem can be caused by not following the manufacturer's instructions about first fitting, or the correct time for replacement. Or of course a faulty filter. However some wall mounted in wall (intercooler) filter systems had two inboard pipe spigots (spitfire), one was filtered water, the other was not, the unfiltered connection was supplied blanked off and if it was wanted needed to be opened up it was destined for the hot water system, and the filtered only for the cold taps. Not all caravan manufacturers used the dual connections, preferring (prefering) to filter all water.

 

[stastanley]

Hi All,

First post - any advice welcome!

We have a Lunar Premiere clubman and have just replaced the boiler Carver Cascade 2 GE (old one was disconnected / partly in pieces so assumed redundant).

Everything seems to work and we get hot and cold water through the sink and shower, the only issue is the water pressure (both hot and cold are very poor).

This might be a bit of a daft question but we're not sure how good the water pressure should actually be for such an old model! It really is a trickle - we were never expecting Niagra falls but it's not really enough for the shower to work (hard to describe). Can I tack some way to get enough pressure in shower?

Would replacing the submersible water pump make any difference? I would have thought the cold water would at least come through at a faster rate.

Thank you in advance!

For adding water pressure to the shower, you can look for something called "high pressure shower head" on the market. As its name says, it is different from ordinary shower heads in that it can increase water pressure. Sorry, I don't know the specific principle. After I replaced such a shower head, my shower improved greatly, and the water flow no longer crawled slowly over my back. This saved me a lot of time.

 

[otherclive]

For adding water pressure to the shower, you can look for something called "high pressure shower head" on the market. As its name says, it is different from ordinary shower heads in that it can increase water pressure. Sorry, I don't know the specific principle. After I replaced such a shower head, my shower improved greatly, and the water flow no longer crawled slowly over my back. This saved me a lot of time.

check the small “gauzes” on the tap outlets if fitted. They unscrew and tend to block over time if used with hard water. Clean using vinegar or descaler.