Replaced calorifier problem

[Rebotco]

Just replaced 50 litre horizontal calorifier with coil for engine heating and coil for Alde heater. But I have got air in the system whilst refilling which is causing the pump to overrun, pressurising the tank, and hot water coming out the cold tap for the first minute or so.

Anyone here know a quick/easy way to get rid of trapped air in the water system????????

It has a PAR MAX 3 pump, a 2.5 Bar PRV and a bleed screw (which only shows a jet of water when opened, no air)

[DHutch]

I get the air out of ours by opening the top pressure release valve, but if yours and your bleed is letting out water, have you tried bleeding air out of the runs to infrequently used taps?

 

We also have a non-return valve on the cold feed to the tank.

 

 

Daniel

[dor]

Heating the calorifier will also pressurise it.

 

Do you have an accumulator?

 

Do you have a NRV on the cold feed to the calorifier?

 

It is almost impossible to remove all air in a horizontal calorifier.

 

By overrun, do you mean the pump keeps running for a while after you turn off the taps? This would be normal if you had an accumulator. If not, the air at the top of the tank is acting like one.

 

A NRV is the answer.

[nicknorman]

Do you have an immersion heater, or maybe a blanking plug where it would be? I so you could slacken off the heater or blank to vent out the air.

 

If you can't get rid of nearly all the air, or if the distance from the calorifier to nearest cold tap s a short one, an NRV is the only solution.

[Rebotco]

Thanks for the good advice and suggestions. Pretty sure that a NRV would cure the symptom, but wouldn't actually deal with the cause. Would it be worth draining all the water down and refilling with all the taps slightly (and perhaps the tank bleed screw) open to give any air a way out whilst filling?

[bizzard]

Here are two methods of bleeding air from a, horizontal calorifier.

1.-- If the pipe work to and from are flexible stand it on end with the PRV uppermost, turn on pump and eradicate air at the PRV, and lay down it again.

2.-- With rigid pipework.---- Hire a tall crane and suspend you boat in the air by its bows, whilst suspended clamber in and bleed air out through the PRV.

If the calorifier is mounted crosswise ''transversely'' careen the boat to the appropriate side and do the same.

 

ps I think a bit of air in the calorifier is a good thing, it takes out the solid water hydraulic kicks delivered to the PRV by the pump as do regulators.

Edited September 1, 2012 by bizzard

[Rebotco]

Here are two methods of bleeding air from a, horizontal calorifier.

1.-- If the pipe work to and from are flexible stand it on end with the PRV uppermost, turn on pump and eradicate air at the PRV, and lay down it again.

2.-- With rigid pipework.---- Hire a tall crane and suspend you boat in the air by its bows, whilst suspended clamber in and bleed air out through the PRV.

If the calorifier is mounted crosswise ''transversely'' careen the boat to the appropriate side and do the same.

 

ps I think a bit of air in the calorifier is a good thing, it takes out the solid water hydraulic kicks delivered to the PRV by the pump as do regulators.

 

I am sorely tempted by option 2 - but think it may be cheaper just to cill the boat!

[bizzard]

I am sorely tempted by option 2 - but think it may be cheaper just to cill the boat!

That wouldn't tip it up enough.

[Rebotco]

That wouldn't tip it up enough.

 

Couldn't I do it sideways?

[bizzard]

Couldn't I do it sideways?

If its mounted transversely and depending on which way round it is yes Careening the boat over to port or starboard on a cill would do the trick.

[Rebotco]

If its mounted transversely and depending on which way round it is yes Careening the boat over to port or starboard on a cill would do the trick.

 

OK. All I need now is a 60ft wide lock.

[RLWP]

Swap the red and blue tops on the taps

 

Richard

[Rebotco]

Swap the red and blue tops on the taps

 

Richard

 

How would that help when hot comes out of both, whatever their colour?

[bizzard]

How would that help when hot comes out of both, whatever their colour?

Discard the blue one and use two red pips.

[Rebotco]

Discard the blue one and use two red pips.

 

Can't help thinking we're not taking this distressing matter seriously enough!!!

[bizzard]

Can't help thinking we're not taking this distressing matter seriously enough!!!

Sorry old bean. It looks like your non return valves ball has furred up and not sealing the flow off from the direction in which intended, or you need a non return valve.

[claudia]

If the primary or hot pipe is to close to the cold then heat transfer will take place and warm the cold water giving a short burst of warm water each time you use it. This is also a very good way of contracting legionares.

[Rebotco]

As a postscript to this thread, I have managed to release most of the offending air by driving a wedge under the PRV end and lifting it a couple of inches. All the symptoms are now 75% better, and I can live with what's left.

Just taken the old leaky tank down the scrap yard and got an unexpected £40 for it! (£3.10 per kilo).