Calorifier problems

[scrambledegg]

If it was full of air, the OP would only have had air coming out of the hot tap.

oops, yes you're right. Missed the bit about OP having good hot tap flow.

OK, another question to the OP. Do you have a thermostatic mixer valve, that moderates hot water out of calorifier to acceptable hot tap temperature? If this had failed it could conceivably output nothing but cold.

[RichardS]

OK, another question to the OP. Do you have a thermostatic mixer valve, that moderates hot water out of calorifier to acceptable hot tap temperature? If this had failed it could conceivably output nothing but cold.

But the hot water from the immersion heater is fine.

Richard

[ip485]

"Can you explain how "the engine feed can now be swaped between the engine and a Hydronic heat source." Is this by valves? How is the pipework connected?"

Yes, valves. The valves enable either engine coolant or Hydronic to be selected.

As to the other questions - yes, a dual coil system would make sense, but thats not what I have at the moment.

As to the coolant, there is no sign of any contamination in the water and the engine was descaled within the last year with Rydlyme.

The system is realtively simple, two pipes run from the Hydronic to the engine bay (hot in and out), in the engine bay there are two T valves, so the coolant from the engine can be switched in or out, and the pipes run on to the calorifier.

What I found inexplicable is why the calorifier heated well on the engine before and doesnt heat at all now.

Thank you for all the suggestions. The system is being professionally installed so hopefully they will soon come up with a solution, but we are all baffled.

Perhaps it could be scale, but it seems very odd this has all of a sudden become a problem and why would it cause just about zero heat transfer to the water in the calorifier.

Oh, and someone ask if the calorifier might not be full. As I mentioned outflow from the hot taps is great, loads of pressure, infact the same as the cold taps and, as I mentioned, the immersion heater in the calorifier heats the water just fine.

[RichardS]

I'm pretty sure that the new pipework/valve and/or its routing/restriction is the problem. Possibly a faulty valve not opening/closing properly but more likely a problem with the pipework routing such that the hot water is not flowing where its supposed to flow.

Carefully checking of the flow by seeing which pipes get hot and which don't when the engine is running should identify the problem.

Richard

[VicS]

Yes, valves. The valves enable either engine coolant or Hydronic to be selected.

The system is realtively simple, two pipes run from the Hydronic to the engine bay (hot in and out), in the engine bay there are two T valves, so the coolant from the engine can be switched in or out, and the pipes run on to the calorifier.

The system is being professionally installed so hopefully they will soon come up with a solution, but we are all baffled.

If these are T- port valves maybe they are the trouble, although one might have expected either the engine heating system or the "hydronic" heating system to work even if the other one doesn't.

I think you should have L-port valves , not T-port ones

If it is being "professionally" installed there should be no problems or bafflement .... It's not exactly rocket science

Can you explain what you mean/ understand by "Hydronic".. The system using the engine is "hydronic". Is "Hydronic" ( capitalised) a registered name which I have failed to find?

Edit

I have found the answer to that last question .... in another recent post of yours! .. Eberspächer HYDRONIC !

[Rogershaw]

If these are T- port valves maybe they are the trouble, although one might have expected either the engine heating system or the "hydronic" heating system to work even if the other one doesn't.

I think you should have L-port valves , not T-port ones

If it is being "professionally" installed there should be no problems or bafflement .... It's not exactly rocket science

Can you explain what you mean/ understand by "Hydronic".. The system using the engine is "hydronic". Is "Hydronic" ( capitalised) a registered name which I have failed to find?

Edit

I have found the answer to that last question .... in another recent post of yours! .. Eberspächer HYDRONIC !

I was also thinking that the Tee valves could be the issue.

The L type have 3 positions on 1 . on 2 one off.

The T type valves have 4 positions on 1 on 2 both on and off.

On the tee valves I use the positions are marked on the valve shaft under the lever.

[duncanmack]

Does your (cold) engine warm up when the Eber is running? If so the valves are the wrong type.

[ip485]

No, the engine doesnt warm. I think the idea is that the Eber either supplies direct to the calorifier, or the engine supplies direct, but it isnt designed so the hot water from the Eber circulates around the engine.

T valves may have been the wrong description on my part. The valves have just two positions, either water from the engine, or water from the Eber, there is obvioulsy one valve for in and one for out.

The professionals are baffled as well at the moment, but will run some more tests and will sort it out I am very hopeful. It is very much their business so I am confident, but thought the collected wisdom here might be very helpful.

I am also of the view that it can only be some sort of flow restriction. I dont see why limescale would suddenly have become a problem, and would limescale in any event result in these symtoms? However, the hot pipe in appears pretty hot, as does the hot pipe out, so a flow restriction also seems unlikely.

[RichardS]

However, the hot pipe in appears pretty hot, as does the hot pipe out, so a flow restriction also seems unlikely.

If the pipe in at the bottom and the pipe out at the top are both similarly hot (too hot to hold), then, as you say, the flow must be fine.

The question then is why that heat is not being transferred to the water in the calorifier .... and that is a real puzzler? How long are you running the engine/other unit for before you are testing for hot water out of the taps? My engine needs at least 30 minutes.

Is the water out of the hot tap starting to get warm after 15 mins and warmer still after 30 minutes or does nothing change as time goes by?

Do you have several hot taps and can you try a different one?

Assuming that the immersion heater in the same water tank is still working well and delivering hot water through exactly the same pipework from the output of the calorifier, onwards, then I'm stumped.

Richard

[superheat6k]

I wouldn't use changeover valves on both inlet and return pipes. Also what creates the flow when using the hydronic heater - does it have its own circulation pump ?

The flow impetus from the engine is typically a take off close to the closed FW circuit water pump, with return to the header tank, but the flow isn't very strong, so it doesn't require much of a restriction to stop the flow.

Certainly your description explains the problem has occurred when the hydronic system has been introduced, so possibly poor plumbing, restrictive Tee valves, perhaps scale or sludge dislodged as a result of the work.

Also have you double checked both engine and hydronic circulation are in the same direction ?

I would dispense with the return Tee valve and consider using simple check valves in the flow from both engine and hydronic unit, using open tees in both inlet and return from the calorifier. Normal flow through the calorifier should be hot in to the upper connection and the cooler return out of the lower, this promotes natural convective flow.

When you find the cause / resolve for your problem please come back here and let us know.