Help Please, I need help with my UFH system setup in France!

[Lisa Brand]

Hi everyone, I am looking for help please on the final set-up/ programming part of my UFH system in France! My husband and I moved over to Normandy 3 years ago and we have renovated an old stone barn into our dream home (physically done all the work ourselves, not like on Grand Designs where they don't even get their hands dirty and have a budget that seems to triple without a sleepless night!) but our UFH system has been a nightmare! We bought the system in the UK and we laid the pipes ourselves as to get a French company to do would have cost over £50k which was nearly our total renovation budget!!! We have a Mitsubishi split unit ASHP, UH8-RF-8 wiring centers, Heatmiser NeoAir Thermostats, Heatmiser NeoHub and Reliance manifolds with Grundfos pumps.
We struggled for over 2 years to get any French plumber to instal the boiler and the ASHP as they haven't supplied it but we've eventually after 3 very cold winters managed to get heat.......Fantastic. But, we just need help with the final set up of the Thermostats etc as we noticed the fitters DIPTest switches (?) have all been left in the ON position so the heating is constantly on. We read the manual and saw that once the system is installed all these DIP switches in the
UH8-RF-8 wiring centre should be in the OFF position, so we did this and the boiler went off and showed the error code 070.
We are looking for someone who would be willing to do a facetime/messenger video consultation (for payment..we're not looking for a freebie!) to help us get this working right. We've left the DIP switches ON as we need heat but we're terrified the system is going to break as it's been on for 2 weeks now. Please please can anyone help? Thanks for your time, Lisa

 

[Brambles]

Hi,

Do not run the system in engineer mode for more than an hour or two maximum. In engineer mode the thermostat protection on the pump is disabled as it the defrost timer. The mode is purely for setting up, balancing and optimising the chilling circuit. Normally, I would expect the unit to lock out after 60 or 90 minutes if left in that mode - It is unusual if it has not locked out.

If you are getting an error code after switching off Engineer mode, the the most likely cause is the chiller temperature differential is not high enough. Code 070 is generic and covers a wide range if issues.

To set it up, you need to post the reasonably detailed circuit diagram - the pump needs to be configured against the expected flow rate and return temperature - unless that has already been undertsken.

 

[Lisa Brand]

Hi,

Do not run the system in engineer mode for more than an hour or two maximum. In engineer mode the thermostat protection on the pump is disabled as it the defrost timer. The mode is purely for setting up, balancing and optimising the chilling circuit. Normally, I would expect the unit to lock out after 60 or 90 minutes if left in that mode - It is unusual if it has not locked out.

If you are getting an error code after switching off Engineer mode, the the most likely cause is the chiller temperature differential is not high enough. Code 070 is generic and covers a wide range if issues.

To set it up, you need to post the reasonably detailed circuit diagram - the pump needs to be configured against the expected flow rate and return temperature - unless that has already been undertsken.

Hi Brambles,
Thank you for your reply I don't think anything has been set up regarding the expected flow rate etc. and we've no idea how to do that. All the videos we've seen online show them adjusting the collars on the decorators caps(?) but the plumber threw them all out when he put the actuators on. We've just bought more but not sure if their needed. I can post pictures when I get back to France on Tuesday but I would really appreciate it if someone would be willing to talk us through setting it up while we do it. We're even willing to pay someone to come over on the Ferry from Portsmouth, we live just by Omaha Beach so we're only 40 mins off the Ferry and we have a Cinema and hot tub and 3 spare bedrooms!!!!!!!! Any One?

Thanks again for your reply, Lisa

 

[Brambles]

Lisa,

If you can post / send details of the the following:

The air source unit model number and the details of the exteral controls fitted - particularly if they are not Mistubishi ( MHI). A copy of the completed commisioming check list ( if completed by the installer).

A sketch to the best of your ability as to what to pump is feeding ( underfloor heating, panel radiators, warm air heaters and or chillers).

The thermal store ( the very big white tank).

Any other external (secondary heating source - wood, coal, oil or gas) feeding the system

Photos to give an idea of layout would be useful.

(Contact details removed - share those via forum messaging system please)

Apologies, I appreciate that the request replicated some of the info that you have already given - but to begin to help remotely I need to know the full system and then try to guess how it has been configured.

Thereafter we will see what we can do for you.

 

[Lisa Brand]

Lisa,

If you can post / send details of the the following:

The air source unit model number and the details of the exteral controls fitted - particularly if they are not Mistubishi ( MHI). A copy of the completed commisioming check list ( if completed by the installer).

A sketch to the best of your ability as to what to pump is feeding ( underfloor heating, panel radiators, warm air heaters and or chillers).

The thermal store ( the very big white tank).

Any other external (secondary heating source - wood, coal, oil or gas) feeding the system

Photos to give an idea of layout would be useful.

Apologies, I appreciate that the request replicated some of the info that you have already given - but to begin to help remotely I need to know the full system and then try to guess how it has been configured.

Thereafter we will see what we can do for you.

Thank You Brambles, I will do that as soon as I get home. I should get back to France late tomorrow so I'll post/email early Tuesday morning (not too early!)

Thank you so much for your time so far, Lisa

 

[Brambles]

Lisa,

That would be very useful and will probably allow us to get to the bottom of the issue. In the interim, I have reread your post and given it some more detailed thought.
I suspect that whoever wired in the Heatmiser control was not familiar with configuring it for heat pump or dual fuel application. They have also not been able to bind the Neo Air sensors - so could not deliver flow to the UFH system. So, to give you heat, get paid and get out - In essence ( I strongly suspect) they have left it with the connections to all zones in the closed position and the Heat Pump set to continuous operation. The latter prevents the MHI Heat Pump from tripping out after 90mins - but if you switch off the demand by opening the dip switches, the Heat Pump will trip on not being able to deliver against a required load.
This would ( as you currently have it) in the short term give you uncontrolled heat. It is exposing the heat pump to damage and - if you have a secondary heat source damage to your floor coverings as the floor surface overheats.

Apologies if that sounds too blunt - but in its current format, I would only use it for short 1 to 2 hour spells.

Is the heat pump controlling your hot water too? If so how is that performing?

In the longer term, you will need someone local to maintain the system, an MHI heat pump, or indeed most brands will fail after 18 months or so if not properly set up and maintained. They are not as forgiving as gas or oil fired boilers if and when left to their own devices.

 

[Dan]

Contact details have been removed from the thread. Please sort this out via the forum. That's what we're here for.