Pipe stats and pumps

[Supertramp]

Hi all....

 

I'm changing the diesel bubble stove for a 4kw solid fuel with back boiler to 3 existing rads and a calorifier.

The 12v existing pump is manually switched (and a bit noisy).

 

As I have access to shoreline 240v mostly, I want to put a 240v circulation pump in, switched via a new pipe stat behind the boiler.

I will need to leave the system whilst at work - so -

As a precaution for pump or 240v failure, I also intended to fit a second pipe stat at a slightly higher temp to switch in the existing 12v pump if something has gone wrong with the 240v one.

 

The pipe layout rules out gravity fed flows.

 

Questions:

 

will the flow in the system be restricted by the 12v pump when it isnt running?

Most pipe stats seem to be 240v ac rated, - do people use them for 12v dc ok? (Jabesco 2amp 12v circulating pump)

 

The calorifier seems to be plumbed accross the end of the flow and return pies. - how do I stop the system cooling down the calorifier if it already has hot water in it?

 

Thanks

Tony

[Bobbybass]

 

As a precaution for pump or 240v failure, I also intended to fit a second pipe stat at a slightly higher temp to switch in the existing 12v pump if something has gone wrong with the 240v one.

 

 

Do you also..take 2 photos of everything..in case one doesn't come out ?

 

bob

[Supertramp]

Do you also..take 2 photos of everything..in case one doesn't come out ?

 

bob

 

LOL - thanks Bob, - am I really worrying too much?

My concern is that someone accidentally/deliberately unplugs the shoreline, - you know it happens once in a while, or what about a power cut whilst at work, -

That could really have an impact if relying on the 240v pump?

[Tony Brooks]

Hi all....

 

I'm changing the diesel bubble stove for a 4kw solid fuel with back boiler to 3 existing rads and a calorifier.

The 12v existing pump is manually switched (and a bit noisy).

 

As I have access to shoreline 240v mostly, I want to put a 240v circulation pump in, switched via a new pipe stat behind the boiler.

I will need to leave the system whilst at work - so -

As a precaution for pump or 240v failure, I also intended to fit a second pipe stat at a slightly higher temp to switch in the existing 12v pump if something has gone wrong with the 240v one.

 

The pipe layout rules out gravity fed flows.

 

Questions:

 

will the flow in the system be restricted by the 12v pump when it isnt running?

Most pipe stats seem to be 240v ac rated, - do people use them for 12v dc ok? (Jabesco 2amp 12v circulating pump)

 

The calorifier seems to be plumbed accross the end of the flow and return pies. - how do I stop the system cooling down the calorifier if it already has hot water in it?

 

Thanks

Tony

 

 

If the 12V pump is a centrifugal one (and I think most are) then it should present very little resistance to flow from the mains pump.

 

Technically you should not use AC only rated switches of any kind for DC circuits because of arching at the contacts as the switch opens under load but I suspect many people do use such pipestats without problems although one should expect a reduced life. If you bare really concerned about contact life use the stat to switch a 12v car type relay which in turn switches the pump.

 

A centrifugal 12V pump will often have its inlet in the centre of the pumping chamber and the outlet at 90 degrees to it stuck out the side.

 

Personally I think your thoughts on this are very wise. Rusty, boiling water being spat out of the header tank is not nice and in an extreme case of stove run away it is suggested there may be a boiler explosion potential although given adequate feed and vent pipe sizes I suspect thats not very likely.

[Robbo]

As I have access to shoreline 240v mostly, I want to put a 240v circulation pump in, switched via a new pipe stat behind the boiler.

I will need to leave the system whilst at work - so -

As a precaution for pump or 240v failure, I also intended to fit a second pipe stat at a slightly higher temp to switch in the existing 12v pump if something has gone wrong with the 240v one.

 

My inverter also acts as a UPS so if the shoreline goes the power doesn't go. If you have a inverter, check too see if it does the same.

 

Note, my inverter wasn't installed correctly to do this, so check the manual rather than physically!

[Supertramp]

Thanks Tony - it looks to be a centrifugal pump from your description, (Jabsco 51590)

I will deff run it through a relay, - as it will reduce the cable size back to the pump.

 

And Robbo, - that sounds a great idea to use the inverter as a UPS, - although mine is always turned off when on shoreline, - also the changeover switches from shoreline to inverter are manual switches, so doubt my set up could run that.

 

Kind regards

 

Tony

[Robbo]

And Robbo, - that sounds a great idea to use the inverter as a UPS, - although mine is always turned off when on shoreline, - also the changeover switches from shoreline to inverter are manual switches, so doubt my set up could run that.

 

Mine is setup this way as well! Making two of the features of the inverter useless (Mine is a Victron so can boost the shoreline amps if needed as well as a UPS), ! I'm re-wiring it, if your comfortable with electrics it's no biggy..

[ditchcrawler]

If the shore line is charging your batteries why not just use a 12 volt DC pump?

[Supertramp]

Good point ditchcrawler - my main concern is a backup pump should one fail while i'm out for several hours.

As the 12v pump is a tad noisy (and mounted centrally in the system - near the bedroom) I wanted a 240 v pump near the stove in the bow, and keep the 12v one as a backup?

 

Mine is setup this way as well! Making two of the features of the inverter useless (Mine is a Victron so can boost the shoreline amps if needed as well as a UPS), ! I'm re-wiring it, if your comfortable with electrics it's no biggy..

 

That sound interesting - let me know how it goes if you can

[smileypete]

Hi all....

 

I'm changing the diesel bubble stove for a 4kw solid fuel with back boiler to 3 existing rads and a calorifier.

The 12v existing pump is manually switched (and a bit noisy).

Maybe run the pump on a reduced voltage, say using a 12V light bulb to drop a few volts.

 

Then if the back boiler goes above say 80°C, give the pump the full 12 volts.

 

Cheap button thermostats on Ebay that could be mounted on the backboiler to do this.

 

Use another button thermostat to start the pump running if the back boiler goes above 50-60°C

 

Also try isolating vibration from the pump using rubber mounts and connecting loops of soft (silicone?) flexible pipe.

 

cheers,

Pete.

[Supertramp]

Thanks Pete, - those button switches look just the job, - and very cheap on ebay.

 

I've tried the rubber mounting for the pump, and it has heater hose connections, - i will try and find a more flexible pipe as you suggest.

 

Enjoy your week

 

tony

[ditchcrawler]

It may have been the setup that caused problems, but when we had a solid fuel backboiler with a button stat on the pipework at the back of the boiler, the boiler "boiled" before the heat transferred to the pipework and stat, switching on the pump. The pump would then switch on, move the boiling water round the system a bit, putting ice cold water into the boiling hot boiler which caused rapped cool down, the pump would then cut out until the boiled boiled again and restarted the cycle. Ideally I think if you do intend to use a pump and stat the pump needs to start as soon as the fire is a light and run continuously until the fire dies.

[Supertramp]

It may have been the setup that caused problems, but when we had a solid fuel backboiler with a button stat on the pipework at the back of the boiler, the boiler "boiled" before the heat transferred to the pipework and stat, switching on the pump. The pump would then switch on, move the boiling water round the system a bit, putting ice cold water into the boiling hot boiler which caused rapped cool down, the pump would then cut out until the boiled boiled again and restarted the cycle. Ideally I think if you do intend to use a pump and stat the pump needs to start as soon as the fire is a light and run continuously until the fire dies.

 

Thats actually a very important point, I guess setting the stat at a much lower temp would solve this, although the idea was not to pump cool water round the system when the fire is nearly out. - I also want to stop it cooling down the calorifier if it was cooler than the water in the tank.

 

Thanks for the help

Tony