Help! Heating Question
I’m hoping Master Plumber will weigh in on this, or someone else with plumbing and heating knowledge We have a brand new hot water heating system, Weil Mclain Mod Con boiler, lovely VEHA radiators but a few problems are surfacing. First, the boiler has a tendency to shut off and leave an error message of…
I’m hoping Master Plumber will weigh in on this, or someone else with plumbing and heating knowledge
We have a brand new hot water heating system, Weil Mclain Mod Con boiler, lovely VEHA radiators but a few problems are surfacing. First, the boiler has a tendency to shut off and leave an error message of “supply too fast.” Since the house is really well insulated we often don’t notice until we try to take a shower (indirect water heater off the boiler) and can’t get any hot water but now we have tenants and are more worried about it shutting off for them. The plumber who installed showed my husband how to adjust the supply but we still have the problem quite frequently. I begin to suspect it might be the boiler itself, I’ve heard nasty internet rumours about this problem with Weil Mclain. Thoughts? Possible causes other than faulty boiler?
Second, sizing radiators. We recently realized when we finally turned heat on for the bottom two floors of our house that the radiators in our house are, for the most part, horribly undersized!! But the weird thing is that with the exception of one slightly colder room, the upper floors are heating just fine (those radiators are undersized too) but the 2 bottom floors won’t warm up. Each floor is its own zone, and the worst is the bottom floor. Any thoughts about radiator sizing/caculations? SHould I replace all the radiators that I know are too small, or should I just replace the ones on the bottom floors? Recommended easy way to calculate? I’d been told room volume *3 for halls, *4 for bedrooms, *4.3-5 for living space. Is this a good shorthand calculation?
I put an ultra in my house. Similar error code. Review the built condition and compair it against the diagram. On mine the plumber used undersized pumps and one burned out.
did the plumber pipe in the primary/secondary loops according to the ultra diagrams?…if the primary loop or secondary takeoffs are incorrectly spaced, you need to replumb in the basement…there should also be modulating valves installedon the pumps that would allow you to balance the heat going to the various floors…is this raisa from park slope?
LOL!
You know me too well, Denton.
The fact is, it’s posts like this one that make me seriously consider limiting my involvement on this blog.
There are really only two reasons the Weil-McLain Ultra shows that error code. Do I reveal them to the OP or do I let the out-of-his-league-and-undercutting plumber figure it out for himself?
How about something in the middle? RAR, if your plumber’s not going to read the boiler Installation and Operation Manual, maybe you should. The answer is in the piping schematics.
that was work ON the settings…
Here comes Master Plumver on another job that got bid at half off!!! lol…
You bought a system from someone who can’t even do basic heat calcs. The radiator OEM shouldn’t be the one doing these cals, there are all kinds of other factors including insulation, windows, etc. Your installer should have done this and if he didn’t do it right you should complain to him.
Now, on the ‘supply too fast’ thing, I’m far from an expert, but what I discovered in my system is that these boilers are more computerized than ever, and even some of the best installers can’t get it right. THere are all kinds of settings that involve ‘ramping’, ie, how fast the water comes in, how fast the boiler comes on, etc. If your installer can’t deal (and if he can’t even size rads what would one think that he could) you need to (a) RTFM and work one the settings and (b) insist that your installer contact tech support at the factory. And listen in when he does.
Hey, OP here,
I know the upper floor radiators are undersized because I got on the phone with VEHA to ask them about the bottom floor rads (they are the ones who originally undersized them) and they did calcs and said “well, the reason why your bottom floor isn’t heating is because that room needs a 7800 btu radiator and yours is 6200” So I asked them about the top floor rooms and even though that’s heating, all those radiators are technically too small, too (i guess they’re okay because heat rises, though?). And yes, the radiators have been bled. And yes they are heating up. But during that cold snap, rads were on 24hrs/day on bottom floor, heat never made it above 55-59 (thermostat set at 59) and now that thermostat set at 65, can’t make it above upper 50s still.
oops, hit post before completion. add: if heat is ok on upper floors, how can radiator be undersized?!
also, do you lower radiators not warm up? if so why do you call them undersized? they may be fine if they heat up.
you need to do a heat load calculation. sizing is dependent on all kinds of factors, and estimation will lead to errors.
“the upper floors are heating just fine (those radiators are undersized too)”
contradictory