Jump to content

Hot water systems


Featured Posts

Hi folks, more questions I'm afraid! I've stripped our old house' solid fuel Rayburn Royal down to its baseplate to refurb it and also lift it into the boat. It has (now) a cast iron back boiler and ready for me to put it back together with new bricks, side tins etc. We have vertical hot water cylinder which has two coils. Bottom one will be plumbed from the Rayburn, top one from the Ruston. The Ruston circuit has an expansion tank in the engine room, the Rayburn one will have an expansion tank higher than the highest point, each circuit will hopefully run a radiator as well, to be decided. So to the question! The domestic hot water in the cylinder, does that need a vent (plus a header to fill it, and therefore only gravity feed to the taps which would be a bit rubbish!) Or is it the norm to rely on a pressure release valve in the domestic circuit, giving pumped hot and cold from a single pump back at the cold water tank? Anyone got a schematic they could share specifically for a solid fuel cooker? We are hopefully going to be able to run the Rayburn circuit without any pumps (thermosyphon??) Anyone got any experience of this?

 

Many thankings,

 

Ian.

Link to comment
Share on other sites

Header tanks for the engine and Rayburn circulations. No header tank or vent for the domestic hot water, but you do need a PRV, and if there is a non return valve on the calorifier inlet you should have an expansion vessel on the hot water side.

Link to comment
Share on other sites

My Rayburns were stoves, not cookers.

I would suggest that you check that stove's output. My experience of two domestic Rayburns was that the will heat whole semi-detached houses central heating and hot water so a calorifier and a single rad may well have it regularly boiling. I think I will drive a gravity system well though but I would probably fit a pump as back up "just in case".

 

As both above, the DOMESTIC water system is sealed so does not require a header tank but a PRV is mandatory and an expansion tank as well as an accumulator a good idea. The central heating system, including the feed to the calorifier, does need  a header tank and vent, especially if I am right about the output. Site the header tank so when/if it spits rusty antifeezey boiling water out nothing important will be stained or damaged.

 

Some bits about domestic water systems here tb-training.co.uk, look in the maintenace notes.

Link to comment
Share on other sites

  • 1 month later...

Go for thermosyphon only. using a pump on such a large solid fuel heat source is in my opinion unsafe. In pump failure you could be faced with uncontrollable boiling and steam production, not pleasant. 

I would suggest that you use the top coil in the calorifier to enable you to get a steady rise on the circulation pipework. This should enable you to use 22mm pipes rather than 28mm.

The engine pump will cope with a non gravity circuit with ease, but take the flow into the bottom of the bottom coil to aid air bleeding and increase heat transfer by a noticeable amount, putting the hottest water into the coolest region. 15mm pipe should be OK if you avoid elbows and use bends.

A steel calorifier is your best bet, copper is very expensive in the thickness required for full fresh water pump  pressure.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.