Which type of antifreeze do people use in their back boilers?

[Tony Brooks]

7 minutes ago, Piran said:

Well, we have a header tank but no expansion tank... 

 

There also isn't a drainage system 

Do you know if having a header tank in fact means that it is an open/vented system? 

As long as the header tank has a non-sealed top it's an open system. the header tank is the expansion tank which is why you should never fill it above about half full when cold.

 

The fact that no one has fitted a drain valve or that you have not yet found one means little, just that a clot installed the system.

 

Try looking behind the rear bulkhead in what may be the engine compartment. Sometimes a pipe is extended through the bulkhead with the drain point in the engine area. If not its just a very boring and potentially messy job. A couple of roasting tins may fit below a rad valve where you can loosen a connection to drain into one tin,  as its fills you change it for a fresh one and empty it into a bucket and repeat.

[Jen-in-Wellies]

16 minutes ago, Tony Brooks said:

just that a clot installed the system.

No shortage of them fitting out boats over the years. Just because it makes no sense, doesn't mean someone hasn't done it that way!

[rusty69]

On 09/10/2020 at 21:10, Jen-in-Wellies said:

In my open vented back boiler central heating I use this stuff.

https://www.screwfix.com/p/flomasta-0623-concentrated-central-heating-inhibited-antifreeze-5ltr/4409r

Propylene Glycol is used for the antifreeze component, so is non toxic. I'd drain it down and fill from empty, so you know you've got the concentration right. You may find air locks afterwards that need bleeding out. The anti corrosion components are as important as the antifreeze one, if not more so and this has them too. Screwfix have branches in cities and towns of any appreciable size.

Jen

Holly thread revival.

 

Would you happen to know the lifespan of the flomasta stuff, I.E how often it needs replacing to retain its antifreezing capabilities?

 

I presume the antifreeze component and inhibitor degrade at different rates.  

[Tracy D'arth]

The antifreeze property will not degrade unless it is diluted. Its the anticorrosion gets used up though.

[Jen-in-Wellies]

4 minutes ago, rusty69 said:

Holly thread revival.

 

Would you happen to know the lifespan of the flomasta stuff, I.E how often it needs replacing to retain its antifreezing capabilities?

 

I presume the antifreeze component and inhibitor degrade at different rates.  

Afraid not. I end up replacing a little each year with more at the same concentration, as it evaporates from the open vented tank, so hopefully there is still some corrosion inhibiting going on. I suppose a dose of the regular inhibitor would be a good idea every once in a while.

To add,

I got the antifreeze/inhibitor for the solar hot water system, as there is still liquid in the solar collector in winter, so it needs protecting from freezing. Since inside the cabin it doesn't get a chance to freeze up, regular inhibitor would have been fine, but since I already had the antifreeze version, that's what I used.

[rusty69]

8 minutes ago, Jen-in-Wellies said:

To add,

I got the antifreeze/inhibitor for the solar hot water system, as there is still liquid in the solar collector in winter, so it needs protecting from freezing. Since inside the cabin it doesn't get a chance to freeze up, regular inhibitor would have been fine, but since I already had the antifreeze version, that's what I used.

I'm looking for the most cost effective solution to prevent the pipes/backboiler from freezing next week. Currently the system just has water in it. I guess car antifreeze would meet the criteria, which seems to be 2 or 10 year, but if the flomasta stuff is also 10 years with the added bonus of inhibitor, I will go for that. 

[Jen-in-Wellies]

I've used up the last of the current batch, unfortunately and don't have the bottle to check any lifespan recommendations. There may be something online, but Screwfix only give the MSDS.

The antifreeze component is propylene glycol, if that helps.

[blackrose]

If it's just the anti-corrosive property that needs a boost I just chuck in a bit of Ankorsol to extend the lifespan of the antifreeze.

 

https://www.morrislubricantsonline.co.uk/ankorsol-anti-corrosion-fluid.html

 

Edited January 12 by blackrose