Perplexed - one for the plumbers

[GreiginFife]

I replaced a big radiator in our hall last night. Straight swap out with some minor pipework due to size difference between old and new.
I followed normal protocol, off went the boiler, shut off the header tank and then drained the system down.
I then had a pizza, not important to the story but it was tasty (smoked sausage, onion and beans for thise that might care).
So, back to the rad, fitted the new one and tightened and checked all my joints. Closed the drain valve and then refilled the system and rechecked the joints. Lovely I thought, no leaks.
So I bled the new rad of all air and then did the same for the rest of the rads and fired up the boiler.
So far so good. Then... boiler stops firing. Checked thermostat, still asking for heat.
Went round all rads and rechecked bleeding. There are 9 rads on the system, 4 get hot and 5 dont. Of the 5, 2 have heat at the flow pipes and 3 dont.
Of the 4 that get hot, its random 1 downstairs and 3 upstairs but not in any logical order.

Its really baking my noodle. Any ideas as to why this would happen after such a routine swap out?

Cheers
Perplexed, Fife

 

[Fish]

Try shutting down the feeds to them all and then filling them 1 by 1 but from the furthest point first, it could be a pressure issue or that the ones that are not getting fully hot there's a build up of crap in them and they all need flushing!

 

[bigslice]

Are there any zone valves, find them open them with power off, why beans on a pizza

 

[Matty6]

Yeah, it sounds like they need balancing. Do what Fish suggested regarding 1 by 1 and furthest first.

 

[williamalex1]

Check if there's an air eliminator near the hot water tank, and the pump is working.

 

[6inchcup]

check header tank not blocked,or valve stuck,manually open zone valve on the heating system ( dont turn on system when filling ) go round to each radiator and fill,if you think it is air locked dont try using the pump to shift it it will not work,you will have to attached hose pipe to downstairs drain valve and fill till no air comes out of hose,ps dont forget to run hose outside and refill with addatives.

 

[GreiginFife]

Are there any zone valves, find them open them with power off, why beans on a pizza

Davie, there are 2 two-zone valves fitted although neither clear as to what each does. When you say power off, do you mean electricity off? They are hardwired with no switches so would need to kill the ring.

Beans on pizza is immense. Like a massive cheesy beano with tomato sauce.

 

[GreiginFife]

check header tank not blocked,or valve stuck,manually open zone valve on the heating system ( dont turn on system when filling ) go round to each radiator and fill,if you think it is air locked dont try using the pump to shift it it will not work,you will have to attached hose pipe to downstairs drain valve and fill till no air comes out of hose,ps dont forget to run hose outside and refill with addatives.

Are you suggesting I bleed the system from the drain valve? Its outside anyhoo so no worries on hoses etc.

 

[Hickory_Hacker]

Deary me ... With genuine interest this has now turned out to be a good thread and hey with a pizza flung in, happy days :thup:

 

[GreiginFife]

Deary me ... With genuine interest this has now turned out to be a good thread and hey with a pizza flung in, happy days :thup:

I could fair go another one Mr D. Good pizza is hard to find.

 

[Hickory_Hacker]

It's one thing being a skinny runt but what's happening with your heating?

I've never put beans on a pizza but I will the next time

 

[paulw4701]

hi if you are still having problems give me a ring (mod Edit)

 

[GreiginFife]

It's one thing being a skinny runt but what's happening with your heating?

I've never put beans on a pizza but I will the next time

In the process of draining the system down again. See if refilling it makes any odds.

 

[Hickory_Hacker]

In the process of draining the system down again. See if refilling it makes any odds.

Perfect timing, phone the helpline above :thup:

 

[PhilTheFragger]

hi if you are still having problems give me a ring (mod Edit)

Generally not an idea to post phone numbers on any public forum.
Send it by PM,

You got a massive air block in there, I find a Mighty Meaty 1/2 & 1/2 with a Meateor is great at shifting it......

Oh radiators, ..........

 

[GreiginFife]

Generally not an idea to post phone numbers on any public forum.
Send it by PM,

You got a massive air block in there, I find a Mighty Meaty 1/2 & 1/2 with a Meateor is great at shifting it......

Oh radiators, ..........

Doesnt seem to be an airlock. I drained the system again, fully opening all the bleed valves until nothing was running from the drain valve.
Closed all the bleed valves and then refilled the header tank. Refilled all the rads one by one, loads of air and then all had water.
Switched the boiler back on and hey presto... same as it was. Heat to 2 out of 5 downstairs (including one of the two in the livingroom right next to ech other) and 3 out of 4 upstairs.
Its quite annoying now but nothing more I can do tonight. No amount of bleeding and closing of lockshields etc seems to work.

 

[williamalex1]

Doesnt seem to be an airlock. I drained the system again, fully opening all the bleed valves until nothing was running from the drain valve.
Closed all the bleed valves and then refilled the header tank. Refilled all the rads one by one, loads of air and then all had water.
Switched the boiler back on and hey presto... same as it was. Heat to 2 out of 5 downstairs (including one of the two in the livingroom right next to ech other) and 3 out of 4 upstairs.
Its quite annoying now but nothing more I can do tonight. No amount of bleeding and closing of lockshields etc seems to work.

Did you check if there is a air eliminator at the hot water cylinder ??

 

[GreiginFife]

Did you check if there is a air eliminator at the hot water cylinder ??

There are no openable valves or similar on or round the cylinder. Only valves in there are two 2-zone Honeywell diverter valves.

 

[williamalex1]

There are no openable valves or similar on or round the cylinder. Only valves in there are two 2-zone Honeywell diverter valves.

It doesn't look like a ordinary valve , more like a pressure release thingy sticking up on the end of a half inch pipe. Google air eliminator valves for some pictures :thup:.

 

[GreiginFife]

It doesn't look like a ordinary valve , more like a pressure release thingy sticking up on the end of a half inch pipe. Google air eliminator valves for some pictures :thup:.

Would that cause random radiators to be hot and some cold?

Cant recall seeing anything like that or similar in the tank cupboard.