Radiators not heating up.

[FlyingFish]

I think your getting a bit confused and hung up on what the manual is telling you. It is referring to the cold water inlet, which has strainer inside the iso valve (15mm cold inlet) and a filter inside the flow switch. And not related to your problem.

What I'm telling you to do isnt listed in the Baxi manual.

Turn the power off
Isolate the boiler using the CH iso valves far left and far right.
Drain the boiler of heating water.
Look at the far right 22mm heating return valve
Put a spanner on the largest of the front facing nuts and undo it. Not the one above connecting to the brass body.
Once removed you will see a tubular strainer similar to that you found in the cold water inlet valve.

Have fun

 

[FlyingFish]

This is the Baxi filling loop kit that can be fitted across the cold inlet and ch return valves.

http://www.directheatingsupplies.co.uk/baxi-5119495-filling-loop-kit

It just means you have to remove it to get to the ch return strainer if its been fitted to your boiler.

 

[jeff the gasman]

What flying fish says is sound advice.

 

[MisterFish]

I think your getting a bit confused and hung up on what the manual is telling you. It is referring to the cold water inlet, which has strainer inside the iso valve (15mm cold inlet) and a filter inside the flow switch. And not related to your problem.

What I'm telling you to do isnt listed in the Baxi manual.

Turn the power off
Isolate the boiler using the CH iso valves far left and far right.
Drain the boiler of heating water.
Look at the far right 22mm heating return valve
Put a spanner on the largest of the front facing nuts and undo it. Not the one above connecting to the brass body.
Once removed you will see a tubular strainer similar to that you found in the cold water inlet valve.

Have fun

Right, that makes more sense. I think I see what you're getting at. Thank you.

I don't have a baxi kit, instead I have a contrivance made from a flexible tap connector hose with two valves, fitted by the guy who put in the boiler. The baxi kit looks a lot neater and I might fit one of those next. Thanks for the heads up.

For clarity the heating return pipe is 22mm but steps down to 15mm before entering the boiler. Sure that is normal and won't make any difference but I thought I'd mention it.

When you say " Drain the boiler of heating water" I am guessing that you don't mean "drain the entire system". If so, where am I likely to find the drain tap to just drain the boiler? Probably a dumb question but, if you don't know, you don't know until somone tell you.

 

[jeff the gasman]

Right, that makes more sense. I think I see what you're getting at. Thank you.

I don't have a baxi kit, instead I have a contrivance made from a flexible tap connector hose with two valves, fitted by the guy who put in the boiler. The baxi kit looks a lot neater and I might fit one of those next. Thanks for the heads up.

For clarity the heating return pipe is 22mm but steps down to 15mm before entering the boiler. Sure that is normal and won't make any difference but I thought I'd mention it.

When you say " Drain the boiler of heating water" I am guessing that you don't mean "drain the entire system". If so, where am I likely to find the drain tap to just drain the boiler? Probably a dumb question but, if you don't know, you don't know until somone tell you.

There's a small drain point inside the case, bottom right. Have a bucket under the filter nut when you remove it.

 

[FlyingFish]

The drain valve is just to the right of the pump, with a little nozzle pointing out of it.
Turning the ch valves off means you are just draining the boiler and not the system.
As a side note, having 15mm check circuit on a 40kw boiler isn't the cleverest of plumbing arrangements!

 

[MisterFish]

Okay, ignore my last, I found it, and thanks for the lightening fast answers there.

The filter is out and cleaned. It was black but in no way blocked or impeded.

Popping out to get fresh washers and then rebuild. I'll let you know how things work once I run the system for a bit.

Thanks again.

 

[MisterFish]

As a side note, having 15mm check circuit on a 40kw boiler isn't the cleverest of plumbing arrangements!

Could you please expand on that?

 

[FlyingFish]

Predictive text meant to say pipe not check!

 

[MisterFish]

Okay, but the inlet fittings on the back of the boiler are 15mm. Aren't they? That seems to be why it has been done at least. What am I missing?

 

[FlyingFish]

Just to be clear, when you say steps down to 15mm are you referring to the pipework under the boiler (system pipework) or the extruded swept bend upto the jig?

 

[MisterFish]

I mean this:

//www.diynot.com/diy/media/img_2162.99223/

 

[MisterFish]

While we're on it, the filters that I have just cleaned seemed to be simple tubes of mesh that sit inside the pipe. Can anyone explain how a mesh around the inside wall of a pipe, seemingly in parralell with the pipe and to the water flow acts as a filter? I would have thought that the filter would need to be across the flow of the water like a fishing net.

Just trying to understand.

 

[FlyingFish]

Your pipe diameter looks 'normal' on your picture

The strainer, does it's job, and is better than nothing. You'll be amazed how many boilers have nothing!
The water does pass through the gauze, but only a small portion of it. It can't be too fine or it would restrict flow too much.

 

[MisterFish]

Okay thanks for all of that.