Eberspacher water heater problems

[wayneybago]

I have a brand new eberspacher hydronic MII water heater connected to my radiators. We are suddenly getting issues. the heater starts up fine. after 11-12 minutes it shuts itself off. There in nothing wrong with the pump (just put another new one on. the fuel is fine. any ideas as I am absolutely freezing here !!!. brrrrrrrrrrr

 

[andy59]

Maybe air lock / faulty pump on radiator circuit ?. If heater fires up and then cuts out when hot its probably overheat lockout.

 

[Greg2]

Maybe air lock / faulty pump on radiator circuit ?. If heater fires up and then cuts out when hot its probably overheat lockout.

+1
We have a hydronic heater and having done some re-plumbing and added a header tank and I can’t get the heater to stay on for very long and it all points to either poor flow rate or an airlock. Engineer advises that if the heater is too hot to keep your hand on then it is overheating and will shut down. I have bought a booster pump to put in the system but have yet to fit it due to lockdown so don’t know if it will help yet.

 

[wayneybago]

Thank for the help. how do I remedy an air lock? or how do i find out if it is an airlock?
We thinkk it might be over heating but how do you fix this problem if it is and what could be causing it. Also are eberspacher fault codes universal. so for example will an 801 controller give me the correct fault codes for an eberspacher hydronic MII unit? will this controller pick up the correct fault codes with my model.

 

[andy59]

I don’t know the fault codes on that unit but the water system must have a filling point somewhere and vent/bleed screws at radiators but without knowing your system can’t be 100%.. Can you locate the circulation pump & feel if it’s running ?

 

[wayneybago]

RIght so now we have bleed the radiators they are fine. we have now just done a circular route of emptying the release valve and pumping the water back round into the filling point. it ran for about 3 minutes cut off and then we heard a small gush of water and the filling tub level went down a bit. so we re started the unit and carried on rotating the water form the release valve while pumping it straight back into the filling unit without loosing water level. and it still got hot and cut off after 12 minutes. the water was getting warmer with every jug we emptied and re filled . but still the unit got hot and shut off !! so cold omg why do these things always happen when its freezing!!!

 

[Greg2]

RIght so now we have bleed the radiators they are fine. we have now just done a circular route of emptying the release valve and pumping the water back round into the filling point. it ran for about 3 minutes cut off and then we heard a small gush of water and the filling tub level went down a bit. so we re started the unit and carried on rotating the water form the release valve while pumping it straight back into the filling unit without loosing water level. and it still got hot and cut off after 12 minutes. the water was getting warmer with every jug we emptied and re filled . but still the unit got hot and shut off !! so cold omg why do these things always happen when its freezing!!!

I feel you pain - I have been trying to resolve our problems for weeks prior to lockdown but I wasn’t staying on the boat so didn’t have the inconvenience of no heat!

 

[andy59]

Is there a fitting to attach a hose at the filling point ? You are aiming to get air out and water in.

 

[andy59]

Are you certain the circulation pump is working?

 

[wayneybago]

The filling station is a tank (see through one on the wall that came with the heater kit. its high up where it should be we fitted the entire kit ourselfs 3 months ago and never had a problem until now. no idea whats wrong . electric blanket and two duvets and plenty of fluff. and a box set. is what will have to do until tomorrow. !!!

 

[wayneybago]

the water pump is working you can feel it and the radiators are getting hot so we know its pumping the water round ok. the unit keeps getting hot just before shut down though as well. as we was rotating water round the system it was getting warmer with every small container full. so we know its going round.

 

[Summer. Wine]

Checked the on/off timer on your control unit?

 

[Greg2]

the water pump is working you can feel it and the radiators are getting hot so we know its pumping the water round ok. the unit keeps getting hot just before shut down though as well. as we was rotating water round the system it was getting warmer with every small container full. so we know its going round.

Sounds exactly the same symptoms as our problem so please keep us posted on how you get on.