i have a potterton 810e puma fitted it is 6-7 years old. it is under homecare aggrement with bg. recently we have had problems with the hot water being very hot..so hot you can't keep your hand under it. bg came out and looked at the problem and changed the dhw and ch sensors and said that was the probelm. since then the problem has still been there. the knob on the front to change the temp doesn't appear to work despite it stating in the manual that it is able to change this between 43-65 degrees. the problem is more noticable now due to us having a thermostatic shower fitted as it now makes the shower go hot and cold...i presume because the valve is shutting off because the water is to hot. the flame light remains on when used with any tap but comes on and off when being used with the shower...because of the valve i presume. i have been told the boiler is hunting? can any one help. flow and pressure appear fine.
hot water on potterton 810e puma
- Thread starter bob2805
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Oh for heaven's sake! It should take a BG engineer absolutely loads of minutes to find out what's wrong!
Haul their sorry **** back in !
You can get a problem with thermostatic mixers where the TM demands less hot when it's sensor gets too hot, but then the water from the combi gets hotter, >> more >> shutoff. But most pumas are ok on that. Try running a tap slow, at about 4 l/min, and see if it does it.
It's a double pass heat exchanger not a separate one for hw so it's less likely to be that than other boilers.
Haul their sorry **** back in !
You can get a problem with thermostatic mixers where the TM demands less hot when it's sensor gets too hot, but then the water from the combi gets hotter, >> more >> shutoff. But most pumas are ok on that. Try running a tap slow, at about 4 l/min, and see if it does it.
It's a double pass heat exchanger not a separate one for hw so it's less likely to be that than other boilers.
funny you should say scaled up as when they were fitting the bathroom the engineers said that it sounded a slight bit bangy but i have never heard it. flow hasn't dropped to my knowledge.is there any truth in this "hunting" theory? hope its not the TM....if it is whats the resolve for that? the shower is Grohe 3000.
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I am glad you have Grohe as they are very good quality products.
Regardless, it is still possible to get interaction between boiler and shower and this depends on boiler setting, water pressure and flow rate and the shower setting.
If the boiler has a temperature control for hot water then BG should be able to get that to work on a tap. A thermostatic shower is a bit more difficult because that will alter the flow rate which in turn will alter the temperature.
Tony Glazier
Regardless, it is still possible to get interaction between boiler and shower and this depends on boiler setting, water pressure and flow rate and the shower setting.
If the boiler has a temperature control for hot water then BG should be able to get that to work on a tap. A thermostatic shower is a bit more difficult because that will alter the flow rate which in turn will alter the temperature.
Tony Glazier
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Cant remember if the Pumas fully modulating (Honeywell or SIT),but do BG engineers have a guage in the toolbox any more because I would have been checking gas pressures agains temperature and flow rate before I changed any sensor and while I was at it I would have used a pendertherm on the primary flow and return to find out just how hot its all getting.
Am I spouting delerious clap trap or is that not the essence of tracing a fault by checking the fundamental things first
Am I spouting delerious clap trap or is that not the essence of tracing a fault by checking the fundamental things first
bob2805,
wondering if you could let me know what was the solution in your case..
we got the same problem, boiler is hunting when any tap/shower is at low flow...(constantly on/off and thus hot-cold-hot cycling water..)
as soon as i open tap fully no problem of hunting (water comes fairly constant hot - but seems bit hot even when set to lower temp. setting on front panel pot)
-- as soon as i replace my shower head with high flow type shower problem disappeared - i think HW demand was high enough and not allowing boiler flame to modulate on/off ..
wondering if you could let me know what was the solution in your case..
we got the same problem, boiler is hunting when any tap/shower is at low flow...(constantly on/off and thus hot-cold-hot cycling water..)
as soon as i open tap fully no problem of hunting (water comes fairly constant hot - but seems bit hot even when set to lower temp. setting on front panel pot)
-- as soon as i replace my shower head with high flow type shower problem disappeared - i think HW demand was high enough and not allowing boiler flame to modulate on/off ..
I looked into the potterton boiler...it is not fully modulating like a modern day condensing boiler. The potterton only has three levels and so cuts out if temperature quite low. I ended up changing boiler to a worcester green star 30cdi.
Thanks, then I think this must be a typical for these old style boilers and it seems I did not notice earlier.
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