Fiamma Aqua 8 issue or installation issue?

[OllieGBR]

I have what I believe to be a simple installation. Fiamma feeds Surecal water heater with one way valve (internal). Off to the left heads to the tap and shower point. Out from the top of the water heater you can see I have an expansion tank fitted to this line and routes to outside shower and tap.
This is my third pump. The first failed after a few weeks blowing the original 10Amp fuse.
The replacement was sucking in air on the exit connector and ‘pulsing’. That was sent back for replacement and the new one appeared to be working fine.
Last night when I opened the tap for the 3rd or 4th time the pump tried to fire up and stopped. It had blown the 5Amp fuse. Replacing the fuse and still nothing.
Either I’m extremely unlucky or the Fiamma pumps are not up to the quality expected. OR
There’s something with my install that’s causing the pump to draw too much current and short out.
OR - something I’m missing?
I’m tempted to replace it with something more rugged?

Care to share any experiences? This is driving me nuts.

Thanks
Ollie.

 

[OllieGBR]

OK - so no thoughts yet and I'm thinking the setup through.

The expansion tank is set to 3.2 Bar, the water pump is a 1.5Bar pump.
Could I draw the conclusion that the back pressure on the pump [from the expansion tank] is too great and it's failing due to being asked to pump at twice the rated pressure?

 

[Dellmassive]

i dont know these systems so im only assuming . .

but if you had a pump capable of 1.5bar . . . then its only going to charge the expansion tank up to 1.5bar?

so the expansion tank would only be at 1.5bar? max? . . . i couldn't see how a 1.5bat pump to get the expansion tank upto 3.2bar.?


what the spec of the pump and exp tank? - maybe some links or pdfs to look at? - well look over the specs?

 

[Pete C]

Do you have a schematic of how it all fits together. I’m no plumbing expert, but it would help us understand what you have.

Pete

 

[Pete C]

I would assume though that the expansion bottle is only there to absorb excess pressure, and doesn’t actually set the pressure of the circuit. The moment you open a tap, the pressure will drop anyway ?

Pete

 

[OllieGBR]

i dont know these systems so im only assuming . .

but if you had a pump capable of 1.5bar . . . then its only going to charge the expansion tank up to 1.5bar?

so the expansion tank would only be at 1.5bar? max? . . . i couldn't see how a 1.5bat pump to get the expansion tank upto 3.2bar.?


what the spec of the pump and exp tank? - maybe some links or pdfs to look at? - well look over the specs?

Great qualifying questions!
The expansion tank is pumped up to 3.2bar with an air pump, I have checked this, (small valve just at the top in the picture below);





I assume that when the hot water expands in the tank it has to go somewhere, so hence the need for an expansion tank.

 

[OllieGBR]

I would assume though that the expansion bottle is only there to absorb excess pressure, and doesn’t actually set the pressure of the circuit. The moment you open a tap, the pressure will drop anyway ?

Pete

That's what I thought. There must be a diaphragm in the expansion tank between the water part, (at the bottom) and the air at the top. The question is does this exert any back pressure to the pump. You can see from the instructions there is a non-return valve built into the heater, again I would assume this would protect the water pump from that back pressure and when you open the tap the 'excess' hot water pressure will exit there.

 

[Robert]

Primary purpose of expansion tank is to reduce any sudden changes of pressure/temperature in the system and therefore protect pump and piping from bursting.
Secondary function of expansion tank is to accumulate some water to provide supply buffer.
For this accumulation to take place the pressure produced by the pump must be at least a little bit grater that expansion tank precharge pressure.

So you need more powerful pump or you need to reduce your precharge pressure(or replace your unit with a lower precharge value).

 

[Pete C]

Surecast website says that the pressure setting for the expansion bottle should be 5psi above your pump pressure.

Pete

 

[Pete C]

You don’t have an accumulator tank on the cold circuit do you ?

Pete

 

[OllieGBR]

Here's a quick schematic of my [simple] system

 

[DXX]

The pressure supplied on the expansion vessel is adjustable. If the pump can only deliver a maximum of 1.5 B there will not be any expansion or accumulation which will lead to the pump pressure switch hunting between set points and quite probably blow the fuse as the pump will have high current draw on repeatedly starting.
This system seems like a waste of valuable van storage space, have you considered a Whale tank mounted pump? There are far simpler shower solutions.

 

[Dellmassive]

fyi . .

Fiamma Aqua 8 pump for caravans and motorhomes

Fiamma Aqua 8 pump

www.fiammastore.com

.

iamma Aqua 8 pumps

Model: Please Select... 12V 7L (1.5Bar) 12V 10L (1.5Bar) Qty: ​

The only self-priming pump with incorporated filter and anti-vibration Silent plate included. The intelligent pump that uses half the consumption of others. The Aqua 8 pumps water vertically over 3m with no priming. Complete with silent plate which eliminates vibrations. The stainless steel filter prevents impurities from entering and is easily cleaned so the pump lasts longer. An automatic pressure switch starts and stops the pump by opening and closing the valve. Non-toxic materials are used for all parts of the pump that come into contact with the water. The pump is resistant to limestone deposits and oxidation. It can run dry without damage. The pump can operate in any position, but we recommend installation by placing the motor on top and the head below to prevent possible damage caused by leaks. Install on a solid surface to reduce noise and vibrations. Easy maintenance: all its components are easily replaceable. (see spares dept) Angle and straight connectors for Ø 133mm pipes included. Standard versions with pressure switch intervention to 1.5 Bar for cumulating Truma Boilers Model RRP Our Price Aqua 8 12V 7L £103.93 £88.00 Aqua 8 12V 10L £105.02 £89.25 Model 12v 7L 12v 10L Power supply V 12 12 Absorption (A) 1.4 3.4 Max flow (L/min) at ) bar 7 10 Noise level (db) 55/60 65/70 Pressure switch interval (Bar) 1.5 1.5 Pressure switch interval (Psi) 21.75 21.75

.

 

[Dellmassive]

what is this refering too?

Standard versions with pressure switch intervention to 1.5 Bar for cumulating Truma Boilers

.

 

[Dellmassive]

is yours the 6Ltr version?

6 Litre slimline 12v/240v Motorhome Water Heater (NO COIL)

SureCal boilers are made of the finest quality materials, which guaranteeing the ultimate performance and reliability. (NO COIL)

www.surejust.co.uk

looks like this one . .






This Surecal comes complete with:

• Thermostatic mixer valve
• 3 bar pressure release valve
• Dual 12 volt 300 watt and 240 volt 700 watt immersion heater
• Non return valve
• Cold, Hot and PRV are ready for 15mm Pushfit plastic plumbing
• Supplied with stainless steel saddles
• No Coil

Surejust > Support

Surejust > Advice and Troubleshooting

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[Dellmassive]

TROUBLESHOOTING


What Pressure is the P.R.V (Pressure Release Valve) set at?
Normally the P.R.V will be factory set at 3 or 4 bar, this can be checked by looking at the pressure rating indicator on the face of the red knob.

Do the dimensions of the cylinders include all fittings and insulation?
Yes, insulation and all fittings suppled as standard with our calorifiers are included within the dimensions stated.

Is an accumulator tank necessary?
An accumulator tank is usually necessary, we would advise the installation of an accumulator tank as it will help look after the pressure pump and provides a small volume of water to use before your pump kicks in.

How long does water take to heat up to a usable temperature?
Lots of factors will determine the actual heat up time of the water in your calorifier, however as a rule of thumb a 1 KW immersion will take 30 minutes to heat up 10 liters of water to a usable temperature. When using the engine or diesel heaters the entire tank will generally heat up in approximatley 30 minutes.

Can an expansion bottle be fitted upside down and where should it be fitted?
An expansion bottle can be fitted in any orientation, the bottle should be installed after the mixer valve.

The immersion heater isn’t working!
Make sure the manual safety reset button hasn’t popped out. If so identify why this has happened and then reset.

How do you adjust the output water temeperature?
This can be altered by turning the thermostatic mixing valve to a comfortable temperature fully closed (clockwise is 30 °C or fully open (anticlockwise) 65 °C.

Do I need a twin or single coil calorifier?
If you only have one heat source (i.e. one or two engines) then a single coil should be used. If you have more than one heat source (i.e. an engine and a diesel heater) then you would use a twin coil.

My P.R.V keeps dripping or releasing water?
You need an expansion tank fitted or, if you already have an expansion tank, the tank pressure needs altering. When altering the pressure in an expansion or accumulator tank, first switch your pump off and open your taps (cold taps for an accumulator, hot for an expansion tank).

 

[OllieGBR]

is yours the 6Ltr version?

6 Litre slimline 12v/240v Motorhome Water Heater (NO COIL)

SureCal boilers are made of the finest quality materials, which guaranteeing the ultimate performance and reliability. (NO COIL)

www.surejust.co.uk

looks like this one . .

View attachment 109707




This Surecal comes complete with:

• Thermostatic mixer valve
• 3 bar pressure release valve
• Dual 12 volt 300 watt and 240 volt 700 watt immersion heater
• Non return valve
• Cold, Hot and PRV are ready for 15mm Pushfit plastic plumbing
• Supplied with stainless steel saddles
• No Coil

Surejust > Support

Surejust > Advice and Troubleshooting

.

Yes - apologies must be 6 not 10ltr version.

 

[Dellmassive]

fyi . .

2 litre expansion tank

The Surejust expansion tank complements any hot water system and provides a safer and smother water system. It comes pre-assembled and pressure set for easy installation. Mount on bulk head and use push fit plastic plumbing to install.

www.surejust.co.uk

The Surejust expansion tank complements any hot water system and provides a safer and smother water system. It comes pre-assembled and pressure set for easy installation. Mount on bulk head and use push fit plastic plumbing to install.
Fit the pre-assembled and easy to install potable water Surejust Expansion tank to your water system.
This will stop your water system been under unnecessary stress, wasting water through the pressure release valve and provide a great deal of safety!
What is an expansion tank and why should i fit one?
An expansion tank is a safety device used in closed water heating systems such as a when a calorifier is used on a boat. It will absorb excess water pressure, which can be caused by thermal expansion as water is heated, or by water hammer
What size should I fit?
The expansion tank should measure 10% of the calorifier capacity. I.e. the 2 litre expansion tank would work with the 10-22litre calorifier, the 5 litre expansion tank with the 30- 55 litre calorifiers and the 8 litre with the 55-75 litre calorifiers.
Where should I fit one?
It should be fitted after the thermostatic mixer valve on the calorifier but before the first outlet. It comes pre assembled with a connection ready to push straight into a plastic plumbing tee piece.
What does it come with?
It comes pressurised to go with a surecal calorifier (this can be altered) a bracket for mounting, a st/steel strap and a connection ready to go straight into plastic plumbing for an easy installation.
What pressure should it is set to?
Our tanks come pre pressurised to go with the calorifier. If you need to change this then it should be set to a pressure above your pump pressure but below the pressure release valve cut out pressure. This is very important or the expansion tank wont work properly.
Why Expansion Tanks are essential
Products specifications

Attribute name	Attribute value
Capacity	2 Litre
Length	300mm
Width	130mm
Height	150mm

 

[Dellmassive]

from above re accumulator/expansion tank:


What pressure should it is set to?
Our tanks come pre pressurised to go with the calorifier. If you need to change this then it should be set to a pressure above your pump pressure but below the pressure release valve cut out pressure. This is very important or the expansion tank wont work properly.

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[Dellmassive]

the installed parts seem to match up and look ok.

so lets look at the Pump power feed.

a poor feed will cause high resistance, that will cause high currant and issues.

the 10Ltrs pump above states 12vdc @ 3.4A . .

lets look at the connections for your power and ground? - get some pics?

where is the feed coming from?

where is the ground?

can you get a volt meter and get a volt reading accross the pump when - static, no engine.?

can you get a volt meter and get a volt reading accross the pump when - static with engine running.?

can you get a volt meter and get a volt reading accross the pump when - pump running , no engine.?

can you get a volt meter and get a volt reading accross the pump when - pump running with engine running. ?

a restistance reading from the pump NEG lead doWN TO different ground point.?