30 xsi new heat exchanger?

[silverbackaddick]

Hi all,

would be grateful for a bit of help, although i'm sure the answers on here somewhere, i have a glow worm 30 xsi linked up with a megaflow tank beneath with drayton digistat wireless system.

the HW has been working fine but the CH has been off through the summer because 3 rads were off because of building works being done which have now been fitted recently
It was all working fine just a bit of knocking and kettleling and with the odd bit of balancing i eventually had every rad hot but now it dosnt work at all i cannot get CH or HW the pump is working fine (have had it off and checked inside) all radshave been bled the boiler actually kicks in but cuts off when reaching 63 degrees after a lot of banging and then sounds like scale circulating i have had a couple of plumbers round one said its the pump or air and the other a new heat exchanger at £300ish without fitting.

I think i have got rid of the air and the pumps working fine but can you clean or flush through a heat exchanger?? Help please its freezing!!!

 

[mickyg]

On the LHS of the boiler is a hydraulic block which has a brass cap at each end, this is where a DV would go on the combi version. Drain the boiler, remove the caps and take out anything in there, springs, black cr*p etc, then replace the caps. If its blocked anywhere I'd put money on that first.

 

[silverbackaddick]

On the LHS of the boiler is a hydraulic block which has a brass cap at each end, this is where a DV would go on the combi version. Drain the boiler, remove the caps and take out anything in there, springs, black cr*p etc, then replace the caps. If its blocked anywhere I'd put money on that first.

There is piping hot water entering the top of the block and freezing cold in the exit pipe. Also the red pullout valve is dispersing freezing cold water from the outside pipe. Thanks.

 

[twgas]

if the red pull out valve, prv to most people, is continuously discharging you must have left the filling loop on.
if it's hot to it (the hydrolic block) and cold from it, good chance it is, as mickyg says, blocked - dont forget to drain the system before removing plugs.

 

[silverbackaddick]

prv wasnt continuasly running, got some black scale out of block got it running but son as ch demand was given system got air in it again back to square 1

 

[silverbackaddick]

Hi guys happy new year well have had it running heating hot water but as soon as ch is involved it shuts down now cant even get it to fire up so nothing works

 

[twgas]

it's not really clear as to what your problem is, you say it's heating hot water but shut off and nothing works.
Turn heating off, run a hot tap, what happens?

 

[Agile]

TW, its apparently not a combi !

OP have you done the finger test on the pump? ( see FAQ ).

Or just call TW if you are in the same area of Kent !

Tony

 

[twgas]

ok not a combi
wouldn't be surprised if more "black scale" has blocked the hydro-block again.
I've had many boilers needing the filter/return etc cleaning several times in quick succession before the circulation is restored.

 

[silverbackaddick]

No TW its not a combi was getting hot water and central heating after getting air out of the system but now seem to have a pcb problem fault 13 as it wont fire up fan starts but thats about it..

 

[silverbackaddick]

circuit board working cannot get ch working without having hot water on and thermovalve manually open, boiler kicks in then shuts off after banging about sometimes so bad sounds like theres a golf ball inside the boiler, because i can get hot water does this mean my heat exchanger is ok?? also checked hydrolic block again still sounds like air in system rads all bled no air in them

 

[silverbackaddick]

could there be a problem with the expansion vessel if its shot would this be putting air into the system?? when i pressed the valve (like a car tyre valve) twice water came out

 

[silverbackaddick]

aslo sometimes get a bit of steam coming out of bottom of door seal jhust before it cuts out does this mean the seals shot and this is where the air is getting into system?

 

[Agile]

could there be a problem with the expansion vessel if its shot would this be putting air into the system?? when i pressed the valve (like a car tyre valve) twice water came out

Thats certainly not correct.

Leave it pressed and see if water stops or just carries on with more than two litres of water being let out.

If it does stop then repressurise in accordance with the FAQ.

If it does not stop then either replace it or fit a new external EXV.

If the main HE is scaled to the point of bumping then it will need cleaning or replacing.

Tony

 

[silverbackaddick]

cheers tony only a squirt comes out of the valve nothing major is it easy to clean the heat exchanger mate? and will i need new door seal if i take it out?