I have an old Teledyne Laars Mark V heater that is still ticking.
It was working fine until recently, when turned on it starts to knock and vibrate like crazy when it heats up.
I checked the bypass valve inside the inlet/outlet header, and it was not all there.
This valve seems to work by having a spring push a plate against the opening between inlet and outlet, this spring and plate is located on the outlet side.
Surprising, I did find the plate only for only $14 online, so I ordered.
All the other parts seem to be intact.
However, I have my doubts about re-building this.
There is a lot of rust inside, and it seems the original plate breached into the inlet side.
If that is the case, this header is not usable with the original bypass valve as the opening would be too big.
I am wondering if I can do a temporary fix until I buy a new heater.
I was thinking of just sealing the hole between inlet and outlet, thereby removing any internal bypass.
We only use the heater for the spa, and will be there to manually turn it on and off.
If I did this I guess I should also plumb an external bypass so under normal filtering I bypass the heater.
Is this a potential safety issue? Could the return water be too hot?
If so could I partially open the external bypass to cool it down some?
If anyone has some feedback or good advice please reply.
One other note. The manual says the bypass plate that I am missing is made of Lexan, a type of plastic.
Anyone know about Lexan? Will this last forever and it is still in my plumbing somewhere, or has disintegrated and broken to pieces? What are the tricks to find these items?
It was working fine until recently, when turned on it starts to knock and vibrate like crazy when it heats up.
I checked the bypass valve inside the inlet/outlet header, and it was not all there.
This valve seems to work by having a spring push a plate against the opening between inlet and outlet, this spring and plate is located on the outlet side.
Surprising, I did find the plate only for only $14 online, so I ordered.
All the other parts seem to be intact.
However, I have my doubts about re-building this.
There is a lot of rust inside, and it seems the original plate breached into the inlet side.
If that is the case, this header is not usable with the original bypass valve as the opening would be too big.
I am wondering if I can do a temporary fix until I buy a new heater.
I was thinking of just sealing the hole between inlet and outlet, thereby removing any internal bypass.
We only use the heater for the spa, and will be there to manually turn it on and off.
If I did this I guess I should also plumb an external bypass so under normal filtering I bypass the heater.
Is this a potential safety issue? Could the return water be too hot?
If so could I partially open the external bypass to cool it down some?
If anyone has some feedback or good advice please reply.
One other note. The manual says the bypass plate that I am missing is made of Lexan, a type of plastic.
Anyone know about Lexan? Will this last forever and it is still in my plumbing somewhere, or has disintegrated and broken to pieces? What are the tricks to find these items?