Old boiler

[afterhourz]

Sounds like the boiler is 'kettling', caused by the heat exchanger being scaled up (reducing capacity hence it boils)
If a flush n cleanse doesn't clear it it probably needs the heat exchanger cleaning with sulphamic acid, afraid you need a special piece of kit to do it.
Otherwise you need the heat exchanger replacing, on a boiler that age its not economical to.
Mines been kettling for ages still works fine just a little noisy..

 

[sneaker]

oh well thats a bit of a bugger thanks for the info, My boiler works fine as You say just noisy.

To flush the system from the boiler do you use a hose attached to point A on the picture?

 

[wiz569]

It will be old not been replaced as I can remember, here's a pic

View attachment 70942

point A. I assume is for draing the boiler?

point B. has a bleed type connector

point C. also has a bleed type connector.

For future reference points B & C are isolating valves so you can remove the pump without draining the system

 

[sneaker]

Any info on point A looks like an hose can be attached.

 

[wiz569]

Any info on point A looks like an hose can be attached.

Sorry m8 yes it is a drain off,and you can use it to drain your whole system providing the boiler is your lowest point

 

[Him Her]

Wiz has the ball - I agree

 

[sneaker]

Thanks everybody for the help, the pump doesn't appear to have a bleed screw and I can't see one for the boiler either,
It's sounds very like afterhourz described guess I'll have to live it.

 

[cat010]

that pump has a bleed screw on the pump body not on the center of the motor its a very old pump i have not seen one for many years , ketteling is a problem on boilers but more with aluminium heat exchangers, change the pump first its the cheapest option

 

[cat010]

just remembered if you go to the plumbing merchants and buy some fernox boiler silencer and some fernox f1 put it into the system put the boiler heating on for a couple of hours to let it mix in and that should improve things forget the pump for now

 

[sneaker]

Thanks for that cat010 I'll look into that.

 

[afterhourz]

I take it it is gravity fed (tank in loft) ?
Get some cleanser and descaler/silencer (Toolstation > Heating > Central Heating Additives)
Put cleanser in the tank, draw off a couple of litres of water from a radiator downstairs (they'll be a draw off valve on one of them)
Leave in the system for a few days and use heating as normal.
Switch off heating/pump, isolated water to tank and drain all of the water out of the system.
Refill system, bleed radiators and run pump for an hour
Switch off pump, isolated water to tank and drain all the water out of the system.
Add silencer to tank, refill system and tank bleed radiators.
To be honest its not going to quieten it down much but you wont now how much until you try...

 

[afterhourz]

Cat010
Soz mate didn't see photo at 1st ,looks like a cast heat exchanger...a flush wont do any harm....
Yes that pump is well old, agree needs changing

Sneaker
If you don't have cheap arse plumbers merchants try >
Toolstation > Heating > Central Heating Pumps > Domestic Circulating Pump

Also them isolating valves dont look to clever bet they letby and will probably need changing too.

 

[cat010]

your first thread says it clanging an banging i woul change the pump as well m8, your boiler went off the market on 1/1 1985 an your pump is at least 10/15 years old put the additives in change the pump you should notice a difference

 

[wiz569]

And might I also add, start saving for a new boiler

 

[gasman]

I agree with wiz on the new boiler and that pump looks ancient lol, I went to one before Christmas and that was the same, sounded very grumpy and some of the rads further away not getting so hot. Gave it a shot of fernox to clean the heat exchanger and put a new pump in (that was a bit of a mission as it had them conex fittings on). Still sounded grumpy though lol but the rads get toasty and warm now.

 

[n4cer]

Those Dab pumps are one of the best and there cheap compared to Grundfos
Change the pump and flush system as mentioned.
Should help reduce the banging

 

[sneaker]

I've now got a leaking radiator with a broken off valve. If I isolate the pump on the boiler will it stop refilling the leaking rad? Or is there a water cut off to the boiler?

 

[Rumpelstiltskin.]

I've now got a leaking radiator with a broken off valve. If I isolate the pump on the boiler will it stop refilling the leaking rad? Or is there a water cut off to the boiler?

Why dont you start a new thread? People see 10 year old threads resurrected and ignore usually.

 

[sneaker]

This had pictures of the boiler, so I figured it would save messin'. If no one answers I'll maybe start a fresh thread.

 

[avid]

I've now got a leaking radiator with a broken off valve. If I isolate the pump on the boiler will it stop refilling the leaking rad? Or is there a water cut off to the boiler?

Normally you would just turn the valves off on the radiator and replace the radiator but if you can’t do that because of the broken valve.
You will need to turn the boiler off and drain the radiator system of water.
Replace the broken valve and replace the leaky radiator.
Refill the system run the boiler then you will need to bleed any air out of the system.