Powermax 155x - Heat Exchanger

[lgoochy]

I went to remove the heat exchanger and 3 way blending valve on my boiler this morning as the hot water is not as it should be.

I think either the 3 way valve is at fault or the heat exchanger is fouled.

I followed all of the instructions in the manual, i.e. closing the isolation valve from the heat store and also turn the small brass nippled below the DHW pump to isolate the system.

Also isolated the cold water inlet as well.

Proceeded to undo the connections and a little water came out but nothing major and was easily mopped up with a towel.

Then the big problem. Attempted to remove the large nut on top of the pump with a set of dogs and proceeded to unscrew it by hand.

Gush, gush gush. The water kust kept coming and I ended up screwing it back on.

Basically the water got under the floor and has stained the living room ceiling.

Does anyone know how to change this part as the instructions said to drain the pump via the screw on the front which I did. As the boiler is floor mounted I cannot get anything under the pump to catch the water

Any help appreciated

Lee

 

[powell30]

Which pump.....there are 2. If you isolated the right one then i am afraid you have hit the dreaded problem.....the isolators are cr*p and probably don't work and will probably leak to when your turn em back on........try draining the tank.....underneath is a drain cock. ANd open your highest and lowest h/w taps too

 

[petit_pablo]

.try draining the tank.....underneath is a drain cock. [/quote

Best bit on the things!

 

[XKESTONMAN]

i would not touch this boiler unless u know exactly what u are doing.

this model boiler has killed.are u rgi

 

[XKESTONMAN]

if u are rgi,post it in combustion chamber,as u said u wanted to remove heat ex

 

[petit_pablo]

this model boiler has killed.are u rgi

I hope not from the posting otherwise god help us all

 

[petit_pablo]

if u are rgi,post it in combustion chamber,as u said u wanted to remove heat ex

TThink he meant the plate heat ex on the side, main heat ex isnt likely to come out

 

[lgoochy]

Which pump.....there are 2. If you isolated the right one then i am afraid you have hit the dreaded problem.....the isolators are cr*p and probably don't work and will probably leak to when your turn em back on........try draining the tank.....underneath is a drain cock. ANd open your highest and lowest h/w taps too

I did that as well. I connected a hose to the drain cock and run it down the drain. I was not sure if this had a dip tube in the bottom of the heat store as the ammount of water that came from the pump was unbelieveable.

I also emptied the header tank and drained from the lowest couple of rads in the house as I wanted to stick some sludge remover in.

 

[powell30]

the heat ex he is on about is the dhw plate ex.......he is fine changing this. it requires no gas/safety work

 

[lgoochy]

if u are rgi,post it in combustion chamber,as u said u wanted to remove heat ex

TThink he meant the plate heat ex on the side, main heat ex isnt likely to come out

Yes you are correct. It is the DHW heat exchanger which is externally mounted. Not touching anything to do with the gas side of the appliance.

It looked a simple job to begin with !

 

[lgoochy]

the heat ex he is on about is the dhw plate ex.......he is fine changing this. it requires no gas/safety work

powell30.

Yes you are correct. I am actually a pump engineer involved in the offshore industry so I am pretty clued up on pumping systems.

This however has so far cost me a tin of paint for the living room ceiling due to the stains.

I woudl have thought that draining the heat store would have removed all the water from the system, so I cant figure out where the hell it was coming from.

Do you guys have any tips on isolating pumps if the valves pass ?

 

[XKESTONMAN]

ok plate heat ex,big drain down,or pipe freeze

 

[lgoochy]

ok plate heat ex,big drain down,or pipe freeze

Cheers. I was thinking that. In your experience how long does the pipe freeze last if the water is hot in the pipe ?

I will need to take the xchanger off for a while as i need to descale it.

 

[petit_pablo]

Do you guys have any tips on isolating pumps if the valves pass ?

The ball type valves on these boilesr are terrible and will most likely leak when refilled. Suggest you invest in some new ones while you have it drained

 

[XKESTONMAN]

you cant freeze hot pipes , lol let it cool down 24hours time before freezing.
if u got to descale,i would go for drain down,at least your in control,and dont flood the whole estate.