P
paulmul
Hi all
My name's Paul and I'm in County Antrim, N. Ireland. I'm pretty good with pretty much any DIY stuff bar plumbing! I've just joined the forum in the hope that some of you experts will be able to advise me on what might be causing some strange behaviour in an underfloor heating system in the house I bought recently.
The house was built in 2007 and then with the property crash it lay in a watertight but unfinished state until we bought it in Aug 2013. The builders finished it off for us but the heating system was largely present since 2007 (though unused). Upstairs is radiators and all seems fine there; downstairs is underfloor heating (water based within concrete floors) all running off an oil boiler that was installed new in Aug 2013.
We're not too impressed with the underfloor heating as it seems to use a ton of oil but the house never really seems quite warm enough downstairs and it behaves somewhat strangely! It is a pretty big house (3360 sq ft) so it may just be that moving from somewhere a lot smaller I'd underestimated the oil usage. I don't have an oil flow meter etc but have used approx 600-700 litres in the past month for example and it hasn't been particularly cold. However I'm concerned about a couple of things that may be causing or contributing to the issues
The system is Pulsar Infloor with 6 stats controlling 14 loops/actuators. There's a Horstmann H37XL timeclock controlling the whole system (zone 1 - underfloor downstairs; zone 2 - radiators upstairs; zone 3 - hot water). There was originally a Pulsar 'Alpha-Basis' wiring centre but I replaced this with a Heatmiser UH3 wiring centre in an attempt to cure the first problem below. It made no difference but it's what's still there at the minute. All the Pulsar stuff was bought in 2007 and sat in boxes in the house until second fix work took place last summer
Firstly, the whole system switches off for around 1 minute every 20 minutes. We'd both the plumber and the electrician who did the second fix work on the system back to look at it recently and neither could explain this (we don't know who the first fix guys 6 years ago were). In fact the system goes through a loop continuously every 20 minutes. 2 rooms aren't in use at the minute, so we've those 2 turned to frostguard on the stats and the other 4 stats are set to 17 degrees (utility), 18 degrees (hall), 21 degrees (kitchen) and 19 degrees (sunroom). The 20 minute cycle happens whether the time clock has the heat currently on or currently off. It is as follows:
- All 4 zones that have stats turned up are calling for heat
- Zones stop calling for heat one by one
- Whole system stops for 1 minute (turning any stats FULLY up during that period doesn't reactivate the system, pump stops, power to boiler goes off unless upstairs/hot water is active).
- System comes back to life with all 4 zones calling for heat at once when it initially starts up again.
This is really puzzling me as I've thought it through in detail and the only components I could lay blame on were the wiring centre or the time clock (as it's a 'whole system' problem so can't just be one dodgy stat). I replaced the wiring centre as mentioned above with no change to the behaviour. I'm dubious that a timeclock could be at fault as it doesn't matter if the heating is on constant, off, or timed. The "loop" still happens. If the timeclock is on, when the 'pause' occurs the power light in the wiring centre is still lit showing the heat is still "on". I should also point out that if we have our stove lit in the sunroom (therefore generating a load of heat separate to the underfloor system) the stat for that zone sometimes doesn't call for heat when the system is at the start of its loop (which makes sense when that room is so warm already).
What doesn't make sense is why the system stops every 20 minutes and why (with no stove running), all 4 zones magically need heat together at the exact same moment even when the heat isn't on?! Can anyone shed any light on what may be going on here?
Second issue I hope is simpler and may just be a draught or dodgy stat(s). The sunroom and kitchen are open plan to each other and generally feel like they're around the same temperature as each other. As mentioned we've the sunroom stat at 19 degrees and the kitchen at 21. That's because I've noticed the kitchen zone rarely calls for heat for more than a minute or so at the start of the loop I describe above, but the sunroom typically calls for most of the time. I'd hoped by setting the stats to different temperatures that I'd work around this imbalance, but it has made no difference (kitchen still rarely on, sunroom still nearly always on). Does that sound like the sunroom stat's getting a draught from somewhere (nothing is noticeable to me), one/both stats are faulty, or something else? Just seems a bit weird.
Finally, a couple of things that may be useful for info. I've done extensive checking of the stats and loops and am sure that the stats are controlling the loops in the areas they're in as expected. (A couple of them were initially incorrect but these have been corrected.) Also the overall TRV (if that's what it's called when not on a radiator!) for the underfloor heating has the temperature at around 40-45 degrees on the inlet side of the manifold. The outlet can be anywhere from 30 to 50 degrees (yes, the gauge on the outlet sometimes shows a warmer temperature than on the inlet side!). I've tried running the system constantly and on timed periods but regardless these 2 problems are always present. I've also switched the main switch for the whole heating system off and back on several times (trying the equivalent of a computer reboot) to no avail. The boiler is a Warmflow B120HE in case that's relevant.
No problems with the radiators or the hot water, so would love to be able to say the same about the underfloor heating!
Thanks for reading this lengthy post and thanks in advance for any advice you can offer!
Paul.
My name's Paul and I'm in County Antrim, N. Ireland. I'm pretty good with pretty much any DIY stuff bar plumbing! I've just joined the forum in the hope that some of you experts will be able to advise me on what might be causing some strange behaviour in an underfloor heating system in the house I bought recently.
The house was built in 2007 and then with the property crash it lay in a watertight but unfinished state until we bought it in Aug 2013. The builders finished it off for us but the heating system was largely present since 2007 (though unused). Upstairs is radiators and all seems fine there; downstairs is underfloor heating (water based within concrete floors) all running off an oil boiler that was installed new in Aug 2013.
We're not too impressed with the underfloor heating as it seems to use a ton of oil but the house never really seems quite warm enough downstairs and it behaves somewhat strangely! It is a pretty big house (3360 sq ft) so it may just be that moving from somewhere a lot smaller I'd underestimated the oil usage. I don't have an oil flow meter etc but have used approx 600-700 litres in the past month for example and it hasn't been particularly cold. However I'm concerned about a couple of things that may be causing or contributing to the issues
The system is Pulsar Infloor with 6 stats controlling 14 loops/actuators. There's a Horstmann H37XL timeclock controlling the whole system (zone 1 - underfloor downstairs; zone 2 - radiators upstairs; zone 3 - hot water). There was originally a Pulsar 'Alpha-Basis' wiring centre but I replaced this with a Heatmiser UH3 wiring centre in an attempt to cure the first problem below. It made no difference but it's what's still there at the minute. All the Pulsar stuff was bought in 2007 and sat in boxes in the house until second fix work took place last summer
Firstly, the whole system switches off for around 1 minute every 20 minutes. We'd both the plumber and the electrician who did the second fix work on the system back to look at it recently and neither could explain this (we don't know who the first fix guys 6 years ago were). In fact the system goes through a loop continuously every 20 minutes. 2 rooms aren't in use at the minute, so we've those 2 turned to frostguard on the stats and the other 4 stats are set to 17 degrees (utility), 18 degrees (hall), 21 degrees (kitchen) and 19 degrees (sunroom). The 20 minute cycle happens whether the time clock has the heat currently on or currently off. It is as follows:
- All 4 zones that have stats turned up are calling for heat
- Zones stop calling for heat one by one
- Whole system stops for 1 minute (turning any stats FULLY up during that period doesn't reactivate the system, pump stops, power to boiler goes off unless upstairs/hot water is active).
- System comes back to life with all 4 zones calling for heat at once when it initially starts up again.
This is really puzzling me as I've thought it through in detail and the only components I could lay blame on were the wiring centre or the time clock (as it's a 'whole system' problem so can't just be one dodgy stat). I replaced the wiring centre as mentioned above with no change to the behaviour. I'm dubious that a timeclock could be at fault as it doesn't matter if the heating is on constant, off, or timed. The "loop" still happens. If the timeclock is on, when the 'pause' occurs the power light in the wiring centre is still lit showing the heat is still "on". I should also point out that if we have our stove lit in the sunroom (therefore generating a load of heat separate to the underfloor system) the stat for that zone sometimes doesn't call for heat when the system is at the start of its loop (which makes sense when that room is so warm already).
What doesn't make sense is why the system stops every 20 minutes and why (with no stove running), all 4 zones magically need heat together at the exact same moment even when the heat isn't on?! Can anyone shed any light on what may be going on here?
Second issue I hope is simpler and may just be a draught or dodgy stat(s). The sunroom and kitchen are open plan to each other and generally feel like they're around the same temperature as each other. As mentioned we've the sunroom stat at 19 degrees and the kitchen at 21. That's because I've noticed the kitchen zone rarely calls for heat for more than a minute or so at the start of the loop I describe above, but the sunroom typically calls for most of the time. I'd hoped by setting the stats to different temperatures that I'd work around this imbalance, but it has made no difference (kitchen still rarely on, sunroom still nearly always on). Does that sound like the sunroom stat's getting a draught from somewhere (nothing is noticeable to me), one/both stats are faulty, or something else? Just seems a bit weird.
Finally, a couple of things that may be useful for info. I've done extensive checking of the stats and loops and am sure that the stats are controlling the loops in the areas they're in as expected. (A couple of them were initially incorrect but these have been corrected.) Also the overall TRV (if that's what it's called when not on a radiator!) for the underfloor heating has the temperature at around 40-45 degrees on the inlet side of the manifold. The outlet can be anywhere from 30 to 50 degrees (yes, the gauge on the outlet sometimes shows a warmer temperature than on the inlet side!). I've tried running the system constantly and on timed periods but regardless these 2 problems are always present. I've also switched the main switch for the whole heating system off and back on several times (trying the equivalent of a computer reboot) to no avail. The boiler is a Warmflow B120HE in case that's relevant.
No problems with the radiators or the hot water, so would love to be able to say the same about the underfloor heating!
Thanks for reading this lengthy post and thanks in advance for any advice you can offer!
Paul.
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