Discuss Heatmiser UF2 info in the Central Heating Systems area at ElectriciansForums.net

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llywelyn111

Hi

Tomorrow I've got a heatmiser UF2 to wire up, my dad first fixed it but he's on holiday for two weeks now and the plumber has only just finished. The system is on a worcester combi oil boiler, hot water, Heating and 3 zone UFH.

http://www.heatmiser.co.uk/web/index.php/docs/finish/63-uh2-wiring-diagram/297-uh2-v2-wiring-diagram

Has anyone used this system before? Never used heatmiser UFH controller before. Being a oil combi I'll need to use a 3 channel programmer, I presume the Live from the programmer will go into "Boiler Enable" and then switch live LR to the boiler?

Always think UFH are going to be more difficult than they actually are

thanks
 

topquark

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Never used one before. Basically yes, from the diag. you posted.

Not sure why you need a three channel programmer though? The UF2 is supplying the three zones. So you'd only need more than two channels if you want separate/different timings for each of those UFH zones. If you only have the UFH and HW then you'd still only need a two channel programmer (for timing). You can then use stats/probes on each of the UFH zones to control the actuator for each zone.

It has both an LS and LR (live supply and live return (switched live/call for heat)) so that the correct voltage can be asserted on the LR terminal back at the boiler. IE it will supply what's present on LS at LR (so could be say 5V if that's what the boiler needed).
 
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llywelyn111

Never used one before. Basically yes, from the diag. you posted.

Not sure why you need a three channel programmer though? The UF2 is supplying the three zones. So you'd only need more than two channels if you want separate/different timings for each of those UFH zones. If you only have the UFH and HW then you'd still only need a two channel programmer (for timing). You can then use stats/probes on each of the UFH zones to control the actuator for each zone.

It has both an LS and LR (live supply and live return (switched live/call for heat)) so that the correct voltage can be asserted on the LR terminal back at the boiler. IE it will supply what's present on LS at LR (so could be say 5V if that's what the boiler needed).
Hi,

The underfloor is only in kitchen, utility and sunroom, the rest of the house has standard radiators, and then HW. So I presume I need a 3 channel programmer.
 

topquark

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Hi,

The underfloor is only in kitchen, utility and sunroom, the rest of the house has standard radiators, and then HW. So I presume I need a 3 channel programmer.
Assuming you have only the one heat source for the CH and they (client) only want to control CH timing on/off as a whole (and not by zone) then no, you still only need two channel. As the room stat/valve for the rads will work as normal.

If I was doing this I'd use the UF2 in addition to a normal wiring centre, then the LR from the UF2 would control the UFH valve supply and then (via valve) to 10 in the wiring centre for a standard S plan plus approach.
 
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llywelyn111

Thanks for that, I just don't wire enough of these systems to stop self doubting.

Think I have it too easy wiring combis with a built in programmer and a room stat 99% of the time.
 
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llywelyn111

All done and dusted, used a 2 channel programmer and wired it as a S plan Plus. (thanks topquark)
 

keniff

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With these panels, if you have a few actuators on one stat where do you double up or do you link the switched lives on the stats
 

topquark

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With these panels, if you have a few actuators on one stat where do you double up or do you link the switched lives on the stats
Depends on the current requirements for the actuators/additional pumps if needed. You could put the stat in series with each of the actuator(s) you want to control, that gets you by the current requirement (you have a single point of failure then though, if the stat or one of the actuators fail, none will operate).

It would be poor design (and possibly won't meet current building regs) to require multiple actuators per stat though. Normally if you have a separate actuator zone you should have a stat/probe to control it.
 

keniff

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I have one to do soon, some rooms have 4 loops so 4 actuators but only one stat. The panel has 12 zones but only enough room to terminate one actuator per zone, never thought of wiring them in series though thanks!
 

topquark

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In domestic current draw is not likely to be a issue anyway TBH, as the power required is only going to be watts not kilowatts worth. More of a concern for commercial/industrial. Just do the sums first ;) to be sure.

If it's multiple actuators for the same room, then building regs s/b happy (there are new rules about number of controllable zones etc).
 
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