Central Heating

[nb blackbeauty]

Hi All

 

Help Please,Just replaced central heating system which I removed 18 months ago doing fitout on side of boat thinking i could do without it WRONG.

Now all I saved were radiators and header tank,

I have now replaced all radiators and pipe work to back of boat were header tank is.

Now I forget how it joins up.

Header tank has out let at bottem and over flow at top.

 

Thanks

John

[Proper Job]

Am I right in thinking that all of the connection are done to the rads, back boiler etc and you just need to connect to the header tank?

 

If so, connect the bottom (outlet) to a local low point in the system. The 'overflow' to a local high point.

 

Under normal operation the header tank will just sit there gently raising/lower its level to compensate for the expansion/contraction of the water in the system.

 

Is the header tank open to atmosphere or is the system pressurised?

Edited July 18, 2009 by Proper Job

[nb blackbeauty]

Am I right in thinking that all of the connection are done to the rads, back boiler etc and you just need to connect to the header tank?

 

If so, connect the bottom (outlet) to a local low point in the system. The 'overflow' to a local high point.

 

Under normal operation the header tank will just sit there gently raising/lower its level to compensate for the expansion/contraction of the water in the system.

 

Is the header tank open to atmosphere or is the system pressurised?

 

Hi Proper Job

 

Yes makes good sense to me to have outlet to low point and overflow to high point.

But seem to remember that overflow pipe went outside through hull.

Could this have been wrong in the first place has it came with the boat and I have had the boat 8 years.

The pipes and rads only ever got hot/warm 1/2 way down the boat depending on how high fire is.

The fire is a new morso squirrel 22 mm pipes, fire at front, header tank 1 gallon capacity open the atmosphere at back of boat and the boat is 60 feet.

[Chris Pink]

The connector at the bottom of the header tank goes to the highest point of the system (that's why it's called a header tank). The overflow, as you say, goes overboard (or in my case into another bottle).

 

If you have a pressurised (car radiator) cap on the header tank then you can run it with or without this, although there was a heated debate, if you'll excuse the pun between two dorks as to whether or not it was ok to have a basic gravity fed system run pressurised on safety grounds.

 

There is another type of unpressurised system where the tank is just open to the air and the high-point take off pipe drips into the top of the header tank and bottom of the tank goes to the low (although not necessarily the lowest) point of the system. I have this kind of system on one of my boats and it didn't work very well but gravity fed systems can be a little esoteric and so it might have been for a different reason.

 

If you have all the original pipework you can tell which you have because the 2nd will have 2 pipes to the header tank from the main loop and the 1st will have just one (to the highest point).

 

If your system didn't work very well the first thing to make sure of is that you are running in 28mm copper.

 

and you've just reminded me i need to fix my back-boiler and this is probably a good time of year to do this!

Edited July 18, 2009 by Chris Pink

[nb blackbeauty]

Thanks both have now conected, will fill and try out in a month or two.

 

John

[bramley]

i had huge problems with my gravity fed system. as soon as the water got to hot it blew it out the header tank. this happened every night and is connected as you have said

 

just thought i would mention it..

[Smelly]

John, if you want to come and have a shuftie at ours then say so, just give me a coupla days to tidy up

[Chris Pink]

i had huge problems with my gravity fed system. as soon as the water got to hot it blew it out the header tank. this happened every night and is connected as you have said

 

just thought i would mention it..

 

sounds like a big air bubble and/or not enough pipe and radiators to get rid of the heat which can be a real problem running stoves meant to heat 5 radiators in a house.

[bramley]

was on a squiral. 55ft boat, however only one radiator.

 

i should imagine your correct. it caused me no end of nightmares

[Smelly]

was on a squiral. 55ft boat, however only one radiator.

 

i should imagine your correct. it caused me no end of nightmares

 

If it wasn't a bleedin big rad then you didn't have enough to disipate the heat and your coolant was boiling. We've got 3.5Kw of rads on our supposedly 2Kw backboiler, however I have cut the ahem "safety" feature off our Brunel so as to get some proper heat out of it.