Two days away from home and I get home last night to "The boiler broke love"!!
The boiler Glowworm Ultimate (downstairs kitchen) has suddenly decided to pop the overheat trip.
Never done it before and its not the first time we've run the heating this year or anything, just happened out of the blue.
Pipework around the pump (upstairs airing cupboard) (Grundfoss 15-50) very hot an seems pump is running.
Nevertheless having given it a "tap" and removed the bung screw its definitely spinning.
Ive set the 2 way valve into the manual position
Ive bled all the rads (didn't need doing, no air in them at all)
There's heat getting into the bathroom tall towel rad, but very little in the others upstairs and the downstairs ones are all cold.
The system was drained a year or two ago and inhibitor put in , the rad bleed water is crystal clear
There is water in the loft fill/expansion tank
So after a reset the boiler fires up fine until, again, it trips.
So I'm a bit stuck now what to do next.....
My next DIY thought, is that the pump impeller may have failed, though I cant find anything bad about these on the net?
So I'd be grateful for any other input please?
Our Gloworm died after 16 years but it was the main circuit board, in the end we went for a new one.
Defo the pump. Boiler gets to hot before it can pump the water away hence trip. Turn the gas on the boiler down to number1 and try, then on 6 see if there is any difference in time delay. If you know what your doing I could tell you to pull the sensor and try it, but that is only a small time bodge. Be careful.
Sounds like there is an electrically controlled valve that isn’t opening, they’re not always next to the boiler. I’d trace the pipes back to where pipe feeding the downstairs and upstairs splits
quote:
Originally posted by britishtrident
Our Gloworm died after 16 years but it was the main circuit board, in the end we went for a new one.
quote:
Originally posted by sprintB+
Defo the pump. Boiler gets to hot before it can pump the water away hence trip. Turn the gas on the boiler down to number1 and try, then on 6 see if there is any difference in time delay. If you know what your doing I could tell you to pull the sensor and try it, but that is only a small time bodge. Be careful.
quote:
Originally posted by Mr Whippy
Sounds like there is an electrically controlled valve that isn’t opening, they’re not always next to the boiler. I’d trace the pipes back to where pipe feeding the downstairs and upstairs splits
It could still be air. Ours occasionally did what you describe and the only way to sort it was to crack the joint to the pump and let the air out.
Bleeding the rads didn't do it.
Also, try turning the pump speed up if you can.
[Edited on 6/11/15 by SJ]
This is a bit confusing because even if a faulty pump or motorized valve were preventing circulation the boiler's control thermostat (i.e. the
user control) should shut the boiler down long before the overheat trip needs to cut in.
I would suggest that you turn the thermostat right down to it's lowest setting and run it, if the overheat still trips you may have a problem
with the control thermostat.
Would quickly add though that I'm not a plumber and have no experience with this particular boiler.....
got to laugh at all the experts!
so if you can reset the boiler and it fires that discounts the pcb etc in the boiler, boilerstat is a possiblity but rarely do they go wrong on that
type of appliance.
so your system works by turning on the clock, the clock powers your roomstat and cylinder stat if fitted , they in turn open the two zone valves that
have switches inside, they in turn power the pump and boiler. check the levers on the end of each valve to check the valves open when powered up
if the pump is running and you have taken the screw out and the shaft is rotating then all should be well if the impellor was damaged you would
clearly hear it.
next you say you have bled the rads did you get water out all of them ? or did any fail to bleed? header tank is full so if any rads dont have water
coming out then chances are your cold feed pipe is choked, likely to be 15mm coming out of the header tank down to the system tied in around the pump
area or if its older sytem at the hw tank.
open a drain or bleed point and draw off a basin of water to check the headert ank refills the system that will tell you if its clear or not. running
a magnet around the connection will also indicate a choke, if there is a choke the magnet sticks to the corrosion inside the copper pipe.
feel free to pm your email if you meed more help
[Edited on 6/11/15 by hizzi]
quote:
got to laugh at all the experts!
Calm down
I'm looking for any info, as said on a car forum, but were a friendly helpful lot
I rather have a few possibilities even if i can discount them practically or logically
Thank you ALL for your input
As far as I know I only have valve.
All the rads bled clear water
I wondered if the impeller had become detached completely?
Re the flow of water
Using the Immersion heater as I did this morning I had no probelm with the flow of hot and cold to the shower?
using your imersion heater will give you a hot shower/hot water , the water systems are independant of each other
as for valves if your timer gives you the choice of hot water or hot water with heating you may only have one valve. if you can select either hot
water or heating on their own then you will have two valves or one three port valve ie a valve with three pipes to it
i would be surprised if the pump impellor has come off, you can check if you like by shutting the valves either side of it and removing the head of
the pump four 4mm allen screws.
how quick does the boiler trip? if the pump was goosed i would expect it to kettle and boil within a minute or two
your pump will need to be on speed 2 or 3. 3 if your house is large or the rads are piped in microbore
[Edited on 6/11/15 by hizzi]
😂😂😂😂
quote:
Originally posted by hizzi
got to laugh at all the experts!
so if you can reset the boiler and it fires that discounts the pcb etc in the boiler, boilerstat is a possiblity but rarely do they go wrong on that type of appliance.
so your system works by turning on the clock, the clock powers your roomstat and cylinder stat if fitted , they in turn open the two zone valves that have switches inside, they in turn power the pump and boiler. check the levers on the end of each valve to check the valves open when powered up
if the pump is running and you have taken the screw out and the shaft is rotating then all should be well if the impellor was damaged you would clearly hear it.
next you say you have bled the rads did you get water out all of them ? or did any fail to bleed? header tank is full so if any rads dont have water coming out then chances are your cold feed pipe is choked, likely to be 15mm coming out of the header tank down to the system tied in around the pump area or if its older sytem at the hw tank.
open a drain or bleed point and draw off a basin of water to check the headert ank refills the system that will tell you if its clear or not. running a magnet around the connection will also indicate a choke, if there is a choke the magnet sticks to the corrosion inside the copper pipe.
feel free to pm your email if you meed more help
[Edited on 6/11/15 by hizzi]
Hi,
Those three way valves sometime break internally. Lot of them are plastic inside and the heating cooling process can make them brittle. To turn
manually you'd need to remove the plastic electric part and twist the copper valve with an adjustable.
Pull the pump out, chances are impellor has fallen off the shaft.
Boiler on, pump running, no circulation.
Sounds like the microswitch in the valve is broken is it is telling the pump and boiler to run but valve is not open.
Take actuator head off - open valve with pliers and then check circulation if everything OK, replace head. If same suspect pump.
quote:
Originally posted by big-vee-twin
Boiler on, pump running, no circulation.
Sounds like the microswitch in the valve is broken is it is telling the pump and boiler to run but valve is not open.
Take actuator head off - open valve with pliers and then check circulation if everything OK, replace head. If same suspect pump.
quote:
Originally posted by SteveWalker
quote:
Originally posted by big-vee-twin
Boiler on, pump running, no circulation.
Sounds like the microswitch in the valve is broken is it is telling the pump and boiler to run but valve is not open.
Take actuator head off - open valve with pliers and then check circulation if everything OK, replace head. If same suspect pump.
Most valves can be operated manually by moving the lever that sticks out. It may not open fully, but far enough to allow circulation.
Funnily enough we've got no hot water at the moment. The motorised valve has failed mechanically and the immersion heater thermostat has also failed at the same time! If the manual override had not broken off, I'd be able to frig the system in a couple of minutes, but as it is, the water is freezing. As I've been working away all week, my wife has had to put up with cold showers for a few days. I'll have to sort it all tomorrow - as well as picking my everyday car up from 110 miles away, where it is stuck with a failed alternator and a flat battery!
I didn't want to get wet last night so I'll look at the pump this morning.
I did pull the 2 way valve apart though
Looking further at the valve spec its actually 3 way (4073A) I believe, so you can have , water, heating or both. With this in mind and the fact that
the pipework is getting plenty hot on both outlets I've convinced myself for now that the chance of it being totally blocked in any position is
slim, therefore I'm putting it back together for now. I also ran the boiler for a considerable time with it on its lowest temp setting before
bed, without it tripping the overheat, so next stop the pump I think?
Its the pump, from an expert 
quote:
Originally posted by joneh
quote:
Originally posted by SteveWalker
quote:
Originally posted by big-vee-twin
Boiler on, pump running, no circulation.
Sounds like the microswitch in the valve is broken is it is telling the pump and boiler to run but valve is not open.
Take actuator head off - open valve with pliers and then check circulation if everything OK, replace head. If same suspect pump.
Most valves can be operated manually by moving the lever that sticks out. It may not open fully, but far enough to allow circulation.
Funnily enough we've got no hot water at the moment. The motorised valve has failed mechanically and the immersion heater thermostat has also failed at the same time! If the manual override had not broken off, I'd be able to frig the system in a couple of minutes, but as it is, the water is freezing. As I've been working away all week, my wife has had to put up with cold showers for a few days. I'll have to sort it all tomorrow - as well as picking my everyday car up from 110 miles away, where it is stuck with a failed alternator and a flat battery!
If it's a standard three way motorised valve pull the plastic body off, two simple clips, then turn it with a spanner.
quote:
Originally posted by sprintB+
Its the pump, from an expert
[img]View My Video[/img]
We are all in the right area, but I needed to be sure! Apart from anything else the pump was a pig to get at, due to having had built in wardrobes
built around the old airing cupboard location, so needed to be sure befor i hit it
Good work and thanks to the to the LCB collective
[Edited on 7/11/15 by ReMan]