No hot water with Baxi Bermuda 401

[Ian997]

Back boiler is a Baxi Bermuda 401 with fire in front has a B at the bottom. After the system was drained to carry out some work. System was refilled, all rads bleed and water coming out of highest one. Water supply to the hot water tank is fed from a supply tank just above, its upstairs and gravity fed. The stopcock is working and the tank fills fine.

All the rads are hot upstairs, but the hot water is still cold. I assume that there is a airlock in the hot water supply/return, but how can I get rid of it ?

Anybody got any ideas ?

Thanks

 

[namsag]

You can try turning heating off and just having hot water on with boiler stat at max this may boil it up enough to shift the airlock other than that the firefront will have to come off so that the thermostat phial can be removed from its pocket and system boiled up properly

 

[Terrywookfit]

You can try turning heating off and just having hot water on with boiler stat at max this may boil it up enough to shift the airlock other than that the firefront will have to come off so that the thermostat phial can be removed from its pocket and system boiled up properly

Not good advice to hand out to a DIY! IMOHO!!

 

[liverpoolboy]

You can try turning heating off and just having hot water on with boiler stat at max this may boil it up enough to shift the airlock other than that the firefront will have to come off so that the thermostat phial can be removed from its pocket and system boiled up properly

why not just backfill the system with mains pressure cold water, from a low drain off point (either at a rad or at the boiler itself) into the f & e cistern to get rid of the air that way? easier and safer for a diy'er!

 

[namsag]

Liverpoolboy simply because it does not work.

Terry last time i looked this site was called diynot.com. There is nothing rocket science in boiling up a system and if the guy needs to know how to do it he will prob ask. And no gas needs to be touched

 

[liverpoolboy]

namsag - why does it not work? i have heard it does get rid of airlocks via the vent pipe / up and over into the appropriate tank ?

also about your method you are right, there is no gas work involved so there's nothing wrong with it. but how would boiling up the water get rid of air? is it a science thing? i've never heard of doing that before! ... it's intersting.

 

[theoutlaw]

Check your zone valves are working properly first then back fill it.
My system died recently and it turned out to be the thermostat on the boiler (same as yours) it also airlocked after draining down and a back fill with the central heating turned off did the trick.
Turn off the boiler and manually open the valve for the hot water. Make sure the central heating valve is closed though in case you push the air lock into it. If you have a 3 way valve set it to hot water.
To back fill it, find the drain cock nearest the boiler and open it with a hose on it connected to a mains fed tap, you will find the water goes everywhere still, so plenty of towels at the ready. Turn on the tap and let it fill the system that way, get someone to keep an eye on the overflow pipe, as the mains pressure could be too much for the overflow to handle

I also have an old Baxi Bermuda PW2 with a 401 behind it.

Good luck!

Tony

 

[liverpoolboy]

yep as airlock is in h/w close the htg valve (or if 3 port mid leave it on auto (h/w port open)

alternatively if it were htg airlocked you'd reverse this!!

there shouldn't be water if the hose is attached securely with a jubille clip. still good practice to have a towel or 4 ready!! but get someone to stand in the loft until water comesw over the vent/up the cold feed and the level of water in the f & e cistern rises.

then turn off the cold mains pressure tap, close drian valve and remove hose.

 

[theoutlaw]

I always get water squirt out of the drain tap not the hose connection, I hate those things, nearly always leave the washer behind inside it and get all crapped up with paint and dead spiders

Tony

 

[namsag]

Yous are assuming it is a fully pumped system but with it airlocking up on hot water there is more chance it is an old gravity hot water system . Which i am also assuming
Which if you try and back fill the water just goes up the open vent and does not push the airlock out of the way.

Liverpool boiling up is a basic thing for shifting airlocks on cast heat exchanger appliances that we learned within weeks of starting

 

[theoutlaw]

I am not assuming anything, I know it is a gravity fed system as it is the same as mine. Back filling has always worked for me.

Tony

 

[namsag]

Outlaw so do you have motorised valves on your system.
And do you know the difference between gravity fed and gravity HW.

 

[theoutlaw]

Yes and Yes mate.

Tony

 

[namsag]

So becauase your fully pumped system will back fill does not mean a gravity HW system will.
And how do you know what system the guy has .
By gravity fed i would say he means filled from a header tank as opposed to sealed

 

[gas_man_gaz]

lol