No Hot Water

[GiveItAGoIain]

Hi all... Suggestions please.

After recently making alterations to the 28mm flow and return from the boiler to cylinder I now have no hot water. Heating is fine.

Pipes are hot from the flow and warm from the return up to the first floor, but not much above that.

I've checked for airlocks and pushed water through the vent by the F&E tank.

Boiler is an Ideal Mexico Super 460FF if that helps at all.

Iain

 

[Agile]

I suppose it may all depend on the undescribed alterations that you have made to the pipework.

When it is 28 mm that is usually a gravity flow system which needs the pipework to follow certain routes to work properly.

Have you loosened a connection at the cylinder to check that there is water pressure there?

Perhaps a photo of the connections at the cylinder might help? And of your alterations?

 

[sajeel]

you need to ensure diverter valve is working the fact that heating is working would indicate the diverter valve is not working

 

[GiveItAGoIain]

Thanks for the quick replies... Photos to follow soon.

Agile: Alterations were a simple re route in the bathroom to avoid running along a wall. Length is the same.

I've loosened both flow and return to cylinder to see if an airlock was there. Happy to try again.

Sajeel: Sorry, should have said it's a gravity fed hot water and pumped heating, so no diverter valve.

Thanks

 

[sajeel]

In that case the boiler will be heating the tank you should have immersion heater as a backup ?

 

[Agile]

It is not so much the length but the rise in the pipework. It should slope upwards all the way.

Have you introduced an airlock by not having a continual upwards slope? Any high points may reduce the gravity flow effect and will need an air bleed point.

Any practical heating engineer would recognize that it was likely to be an old fashioned gravity system!

Tony

 

[GiveItAGoIain]

Getting somewhere... Thank you Tony.

My alterations may have affected things then. To avoid running the pipes along the wall, I've dropped them under the floor into notches (already there). The pipes run from a void above a kitchen extension into the bathroom and I had to drop them 4" to go through 2 steel RSJs rather than the brick walls above.

Any solutions apart from some very awkward new pipework to ensure the continuity of slope?

 

[GiveItAGoIain]

Immersion works as a back up, but it's not something I want to rely on.

 

[Agile]

100 mm will have only a very small effect on the gravity flow.

But have you formed a high point where air can collect?

If so then fitting an air vent point should restore circulation.

I say "should" because gravity circulation and particularly air locks sometimes seems to defy the laws of physics.

Tony

 

[GiveItAGoIain]

Haha. Just my luck...

I've bled the high point of my alterations, but this was before pushing water through the vent, so I'll try bleeding again after I put in a air vent.

Cheers all, I'll let you know how it goes.

 

[sajeel]

great hope you get sorted hopefully an air vent will bleed system and you will have hot water back, some pics may be helpful

 

[picasso]

Convert it to fully pumped, you seem quite capable of altering the pipework so it aint gonna cost much for another pump or a couple of zone valves.

 

[sajeel]

that is another option go to fully pumped system

 

[GiveItAGoIain]

Picasso... If it's as simple as adding another pump then I might just go that way.

Photos as promised from both sides of the wall. The original pipework went straight through the wall above the RSJs and then followed the bathroom walls. I've dropped them to go through the RSJs and under the floor.

The cylinder has a basic setup with a vent leading to the F&E tank and the F&E tank feeding the other pipe.

 

[GiveItAGoIain]

Okay... Just bled the new high point. No air at all there in either flow or return.