UPS for a heating system – numpty DIY plumber/sparky questions

We live in an area where its not uncommon to have the power go off for an hour or so at a time.
I have the most complicated boiler stove / solar / oil / immersion central heating system in the world that requires electricity to run the pumps.
I’m considering fitting a UPS – I’ve looked at computer UPS like this – http://www.ebay.co.uk/itm/251334475243?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Whilst the load rating is fine, the run time at the expected load is poor – I expect they are really for shutting down a system in a controlled manner rather than keeping them going.

I was wondering then, if you could wire in parallel a leisure battery which would give it a longer run time.

I could go for a complete home brew solution, but I do like the simplicity of a box + battery approach if I can make it work.

Whaddya think?

I have the most complicated boiler stove / solar / oil / immersion central heating system in the world that requires electricity to run the pumps.

You only really need to keep the CH pump going (50W), the oil pump (20W) and the oil solenoid open (2W), so all in it should be less than 100W.

Computer UPS’s typically provide just enough run time to give the opportunity for a graceful shutdown – around 10 minutes at the full load

A lot of UPSs can be bought with additional battery modules, maybe look at one of those.

It can get expensive quickly though. A small petrol generator might be the cheaper option

Geoff I think this is your solution

We used to get lots of power cuts and that had implication for my work. I seriously considered a diesel generator/changeover switches etc. but finally decided to just put up with it. Do you really need the CH on when you’ve got a stove…. it’s only an hour.

Oh and to answer your original question, a UPS would not be very good and they actually use a fair bit of power just being plugged in.

We used to get lots of power cuts and that had implication for my work. I seriously considered a diesel generator/changeover switches etc. but finally decided to just put up with it.

A colleague has just this – they live just outside Cambridge and get power cuts, so had a complete back up system installed for the house!

geoff – Id look at getting a leisure battery, a 400W inverter and a trickle charger. Stick it all in the box in the boiler room with a decent switch over system (so you dont squoosh electrical death back up the grid).

PS – I have all that in the camper van, so I can raid it in an emergency. I too need to run a couple of pumps to get the hot water from the boiler to the right places.

I also have a 2kw generator which is overkill for most things but I got it for building the barn and it wont die so it’s a back up if I need it. I keep a jerry can of petrol for it.

The problem we have is that with the boiler stove on, I really need to run the load charger (laddomat) which is a basic CH pump. The long pipe runs between the stove and the thermal store mean that there is a risk of the charging circuit boiling if the pump isn’t running. The boiling in itself isn’t a problem, as there is a TRV to an outside overflow, but I don’t like wasting the heat and the noise of it boiling upsets Mrs J 🙄

I’m thinking that I might just rig something up to the ch pump on the laddomat so that at least that will continue to pump.

Edit: Cheers stoner, I agree, I think a home brew option may actually be better.

The kind of UPS you will need for this are more like this APS 5000XL one:

(apologies in advance for the jazzy carpet)

You can daisy chain more battery packs (the bit on the left) off the main unit to increase capacity. You could probably bodge something equivalent yourself though…

Small UPS coupled to an electric start generator with something connected between the two so when the UPS kicks in it starts the generator.

Your stove assuming it is solid fuel should have thermal relief is that the trv you spoke about. It shouldn’t be a trv but a proper thermal relief which allows cold water into system.
I have used a UPS in exactly this situation to run a loading pump in event of power failure, had a 30 min run for pump which was enough to get rid of heat.
Lots of boilers need quite high current to start pumps and igniters if you want it to run the whole system.

Bear – I think by “TRV”, geoff means a “T&PRV”.

Ebay for an old server bottom of rack system? Should have more capacity and people want rid as they are so bloody heavy and in the way.

6 months ago I could have passed one on if you’d been able to make it to Uxbridge, was closing a satellite site there.

I did a system for a lady who’s house had a pump to drain a sump in order to prevent flooding during heavy rain. The power was prone to dropping out when the rain came, rendering the pump useless.

We fitted a Victron Energy Multiplus Compact inverter with a leisure battery. The inverter keeps the battery charged and automatically switches over in the event of a power failure. On resumption of power, it automatically reverted to mains operation.

If you want further info. I can let you have it. Email address is in my profile.

Rich.