[Question] Different type of tech, but why not - boiler question

[Bubble181]

There's no subforum for technical questions not relating to the PC, but it would seem weird in the General forum. Eh.

Anyway, my hot water boiler's having issues. It's a gas boiler for both central heating and hot water. Currently it's set to just heat the water, not the CH, for obvious reasons. This morning, I (once again) didn't have hot water. However, if I let the faucet run, the radiators get hot. It seems to be heating the wrong circulation or some such.
Turning both on, or fiddling with the amount of power sent to water or CH doesn't really seem to make much of a difference. Resetting doesn't help either, nor does cutting power for a while.
However, I've noticed that usually, it'll go a bit like this:
1 I don't have hot water
2. I go check on it and the pressure on the heating's too low
3. I put in more water.
4. I don't have hot water, go WARGARBL for a bit, try resetting, opening several faucets at the same time, turning the central thermostat on/off, cutting power, y'know, the usual.
5. I still don't have hot water.
6. I increase the pressure on the heating a little more.
7. Hot water is back and I have a nice long relaxing shower.

Now, so far, I've been able to get hot water running again every time, but I'm just wondering what the heck could be wrong, and what I could do to prevent this from getting worse/something breaking down/happening at all.

Anyone have any insights?

 

[PatrThom]

Automobiles have a thermostat that keeps heat in the engine until it gets too hot, then will finally open to allow the hot water to circulate through the radiator. If this thermostat sticks, your engine gets too hot and it takes longer for the hot water to get to the radiator. Maybe your system has something like this?

--Patrick

 

[strawman]

.



If you're central heating loop volume and pressure are low, you probably have a leak. If you have a leak, it will automatically shut down to prevent damage to itself once it does have enough water in the central heating loop.

The machines I've looked at always heat the central heating loop, and use that loop to heat the hot water. It shuts off the loop to individual rooms when you don't want room heat, but it runs the main loop in order to heat the hot water exchanger. So if the main central Heath loop is having any problems, you won't get hot water.

So double check your water levels and pressures, and test the main loop.


Alternately there may be a switch in your system which is meant to detect when hot water is flowing that isn't working, or you recently installed a low flow shower head and it's not envy flow to trigger the switch.

 

[PatrThom]

I'll be filing this info away for later, as it is likely I will soon be moving to a place which uses a boiler. First time I will ever have lived in such a place. Might run into issues.

--Patrick

 

[strawman]

Also keep in mind that I haven't actually worked on such a system, or had to live with or maintain one. I just like to consume information about mechanical and electrical gizmos, and I'm extrapolating a lot from probably little info, such as websites and pamphlets I may have read about such systems before and related systems in other applications.

I suspect you'll get a lot of expert info from http://diy.stackexchange.com/ if you ask there.

 

[PatrThom]

I think that's both of us, stienman.

--Patrick